diff --git a/core/modules/layout_builder/layout_builder.install b/core/modules/layout_builder/layout_builder.install
index 4a02f2380b..48ce49fce9 100644
--- a/core/modules/layout_builder/layout_builder.install
+++ b/core/modules/layout_builder/layout_builder.install
@@ -8,42 +8,27 @@
 use Drupal\Core\Cache\Cache;
 use Drupal\layout_builder\Entity\LayoutBuilderEntityViewDisplay;
 use Drupal\layout_builder\Section;
-use Drupal\layout_builder\SectionComponent;
 
 /**
  * Implements hook_install().
  */
 function layout_builder_install() {
-  $uuid_generator = \Drupal::service('uuid');
-  $entity_field_manager = \Drupal::service('entity_field.manager');
-
   $displays = LayoutBuilderEntityViewDisplay::loadMultiple();
   /** @var \Drupal\layout_builder\Entity\LayoutEntityDisplayInterface[] $displays */
   foreach ($displays as $display) {
+    $components = [];
+    foreach ($display->get('content') as $name => $component) {
+      if ($new_component = _layout_builder_create_section_component_from_options($display->getTargetEntityTypeId(), $display->getTargetBundle(), $name, $component)) {
+        $components[] = $new_component;
+      }
+    }
+
     // Create the first section from any existing Field Layout settings.
     $field_layout = $display->getThirdPartySettings('field_layout') + [
       'id' => 'layout_onecol',
       'settings' => [],
     ];
 
-    /** @var \Drupal\Core\Field\FieldDefinitionInterface[] $field_definitions */
-    $field_definitions = $entity_field_manager->getFieldDefinitions($display->getTargetEntityTypeId(), $display->getTargetBundle());
-
-    $components = [];
-    foreach ($display->getComponents() as $name => $component) {
-      if (isset($field_definitions[$name]) && $field_definitions[$name]->isDisplayConfigurable('view') && isset($component['type'])) {
-        $uuid = $uuid_generator->generate();
-        $configuration = [];
-        $configuration['id'] = 'field_block:' . $display->getTargetEntityTypeId() . ':' . $name;
-        $configuration['label_display'] = FALSE;
-        $configuration['formatter']['type'] = $component['type'];
-        $configuration['formatter']['label'] = $component['label'];
-        $configuration['formatter']['settings'] = $component['settings'];
-        $configuration['formatter']['third_party_settings'] = $component['third_party_settings'];
-        $configuration['context_mapping']['entity'] = 'layout_builder.entity';
-        $components[] = (new SectionComponent($uuid, $component['region'], $configuration))->setWeight($component['weight']);
-      }
-    }
     $display
       ->appendSection(new Section($field_layout['id'], $field_layout['settings'], $components))
       ->save();
diff --git a/core/modules/layout_builder/layout_builder.module b/core/modules/layout_builder/layout_builder.module
index 0b85ab9909..10be312cf0 100644
--- a/core/modules/layout_builder/layout_builder.module
+++ b/core/modules/layout_builder/layout_builder.module
@@ -11,6 +11,7 @@
 use Drupal\layout_builder\Entity\LayoutBuilderEntityViewDisplay;
 use Drupal\layout_builder\Entity\LayoutBuilderEntityViewDisplayStorage;
 use Drupal\layout_builder\Form\LayoutBuilderEntityViewDisplayForm;
+use Drupal\layout_builder\SectionComponent;
 
 /**
  * Implements hook_help().
@@ -62,6 +63,7 @@ function layout_builder_field_config_insert(FieldConfigInterface $field_config)
   /** @var \Drupal\Core\TempStore\SharedTempStore $tempstore */
   $tempstore = \Drupal::service('tempstore.shared')->get('layout_builder.sample_entity');
   $tempstore->delete($field_config->getTargetEntityTypeId() . '.' . $field_config->getTargetBundle());
+  \Drupal::service('plugin.manager.block')->clearCachedDefinitions();
 }
 
 /**
@@ -72,4 +74,36 @@ function layout_builder_field_config_delete(FieldConfigInterface $field_config)
   /** @var \Drupal\Core\TempStore\SharedTempStore $tempstore */
   $tempstore = \Drupal::service('tempstore.shared')->get('layout_builder.sample_entity');
   $tempstore->delete($field_config->getTargetEntityTypeId() . '.' . $field_config->getTargetBundle());
+  \Drupal::service('plugin.manager.block')->clearCachedDefinitions();
+}
+
+/**
+ * Converts field options into a SectionComponent.
+ *
+ * @param string $entity_type_id
+ *   The entity type ID.
+ * @param string $bundle_id
+ *   The bundle ID.
+ * @param string $name
+ *   The field name.
+ * @param array $options
+ *   The array of field options.
+ *
+ * @return \Drupal\layout_builder\SectionComponent|null
+ *   The new section component, if one can be created.
+ */
+function _layout_builder_create_section_component_from_options($entity_type_id, $bundle_id, $name, array $options) {
+  /** @var \Drupal\Core\Field\FieldDefinitionInterface[] $field_definitions */
+  $field_definitions = \Drupal::service('entity_field.manager')->getFieldDefinitions($entity_type_id, $bundle_id);
+  if (isset($field_definitions[$name]) && $field_definitions[$name]->isDisplayConfigurable('view') && isset($options['type'])) {
+    $configuration = [];
+    $configuration['id'] = 'field_block:' . $entity_type_id . ':' . $name;
+    $configuration['label_display'] = FALSE;
+    $configuration['formatter']['type'] = $options['type'];
+    $configuration['formatter']['label'] = $options['label'];
+    $configuration['formatter']['settings'] = $options['settings'];
+    $configuration['formatter']['third_party_settings'] = $options['third_party_settings'];
+    $configuration['context_mapping']['entity'] = 'layout_builder.entity';
+    return (new SectionComponent(\Drupal::service('uuid')->generate(), $options['region'], $configuration))->setWeight($options['weight']);
+  }
 }
diff --git a/core/modules/layout_builder/src/Entity/LayoutBuilderEntityViewDisplay.php b/core/modules/layout_builder/src/Entity/LayoutBuilderEntityViewDisplay.php
index faa4421d1a..246fb521ac 100644
--- a/core/modules/layout_builder/src/Entity/LayoutBuilderEntityViewDisplay.php
+++ b/core/modules/layout_builder/src/Entity/LayoutBuilderEntityViewDisplay.php
@@ -52,7 +52,7 @@ public function getSections() {
    * @return $this
    */
   protected function setSections(array $sections) {
-    $this->setThirdPartySetting('layout_builder', 'sections', $sections);
+    $this->setThirdPartySetting('layout_builder', 'sections', array_values($sections));
     return $this;
   }
 
@@ -67,11 +67,11 @@ public function count() {
    * {@inheritdoc}
    */
   public function getSection($delta) {
-    $sections = $this->getSections();
-    if (!isset($sections[$delta])) {
+    if (!$this->hasSection($delta)) {
       throw new \OutOfBoundsException(sprintf('Invalid delta "%s" for the "%s" entity', $delta, $this->id()));
     }
-    return $sections[$delta];
+
+    return $this->getSections()[$delta];
   }
 
   /**
@@ -105,8 +105,8 @@ public function appendSection(Section $section) {
    * {@inheritdoc}
    */
   public function insertSection($delta, Section $section) {
-    $sections = $this->getSections();
-    if (isset($sections[$delta])) {
+    if ($this->hasSection($delta)) {
+      $sections = $this->getSections();
       // @todo Use https://www.drupal.org/node/66183 once resolved.
       $start = array_slice($sections, 0, $delta);
       $end = array_slice($sections, $delta);
@@ -124,10 +124,24 @@ public function insertSection($delta, Section $section) {
   public function removeSection($delta) {
     $sections = $this->getSections();
     unset($sections[$delta]);
-    $this->setSections(array_values($sections));
+    $this->setSections($sections);
     return $this;
   }
 
+  /**
+   * Indicates if there is a section at the specified delta.
+   *
+   * @param int $delta
+   *   The delta of the section.
+   *
+   * @return bool
+   *   TRUE if there is a section for this delta, FALSE otherwise.
+   */
+  protected function hasSection($delta) {
+    $sections = $this->getSections();
+    return isset($sections[$delta]);
+  }
+
   /**
    * {@inheritdoc}
    */
@@ -193,13 +207,12 @@ protected function addSectionField($entity_type_id, $bundle, $field_name) {
   /**
    * {@inheritdoc}
    */
-  protected function getDefaultRegion($delta = 0) {
-    $sections = $this->getSections();
-    if (!isset($sections[$delta])) {
+  protected function getDefaultRegion() {
+    if (!$this->hasSection(0)) {
       return parent::getDefaultRegion();
     }
 
-    $section = $this->getSection($delta);
+    $section = $this->getSection(0);
     return $this->getLayoutDefinition($section->getLayoutId())->getDefaultRegion();
   }
 
@@ -247,7 +260,7 @@ public function buildMultiple(array $entities) {
       if ($sections) {
         foreach ($build_list[$id] as $name => $build_part) {
           $field_definition = $this->getFieldDefinition($name);
-          if ($field_definition && $field_definition->isDisplayConfigurable('view')) {
+          if ($field_definition && $field_definition->isDisplayConfigurable($this->displayContext)) {
             unset($build_list[$id][$name]);
           }
         }
@@ -383,4 +396,29 @@ protected function getRouteParameters() {
     return $route_parameters;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function setComponent($name, array $options = []) {
+    parent::setComponent($name, $options);
+
+    // @todo Remove workaround for EntityViewBuilder::getSingleFieldDisplay() in
+    //   https://www.drupal.org/project/drupal/issues/2936464.
+    if ($this->isNew()) {
+      return $this;
+    }
+
+    if ($new_component = _layout_builder_create_section_component_from_options($this->getTargetEntityTypeId(), $this->getTargetBundle(), $name, $this->content[$name])) {
+      if (!$this->hasSection(0)) {
+        $section = new Section('layout_onecol');
+        $this->appendSection($section);
+      }
+      else {
+        $section = $this->getSection(0);
+      }
+      $section->appendComponent($new_component);
+    }
+    return $this;
+  }
+
 }
diff --git a/core/modules/layout_builder/src/Form/LayoutBuilderEntityViewDisplayForm.php b/core/modules/layout_builder/src/Form/LayoutBuilderEntityViewDisplayForm.php
index e99ce1edbc..c68f2b77c5 100644
--- a/core/modules/layout_builder/src/Form/LayoutBuilderEntityViewDisplayForm.php
+++ b/core/modules/layout_builder/src/Form/LayoutBuilderEntityViewDisplayForm.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\layout_builder\Form;
 
+use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\field_ui\Form\EntityViewDisplayEditForm;
 use Drupal\layout_builder\Entity\LayoutEntityDisplayInterface;
@@ -28,6 +29,8 @@ public function form(array $form, FormStateInterface $form_state) {
 
     // Hide the table of fields.
     $form['fields']['#access'] = FALSE;
+    $form['#fields'] = [];
+    $form['#extra'] = [];
 
     $form['manage_layout'] = [
       '#type' => 'link',
@@ -71,4 +74,18 @@ public function entityFormEntityBuild($entity_type_id, LayoutEntityDisplayInterf
     $display->setOverridable($new_value);
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  protected function buildFieldRow(FieldDefinitionInterface $field_definition, array $form, FormStateInterface $form_state) {
+    // Intentionally empty.
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function buildExtraFieldRow($field_id, $extra_field) {
+    // Intentionally empty.
+  }
+
 }
diff --git a/core/modules/layout_builder/src/Section.php b/core/modules/layout_builder/src/Section.php
index e183fb6713..20e9dec579 100644
--- a/core/modules/layout_builder/src/Section.php
+++ b/core/modules/layout_builder/src/Section.php
@@ -73,20 +73,14 @@ public function __construct($layout_id, array $layout_settings = [], array $comp
    *   A renderable array representing the content of the section.
    */
   public function toRenderArray(array $contexts = []) {
-    $layout = $this->getLayout();
-
-    // @todo Add the regions to the $build in the correct order. This is done
-    //   for parity with \Drupal\field_layout\FieldLayoutBuilder::buildView(),
-    //   which incorrectly adds all regions to the build.
-    $regions = array_fill_keys($layout->getPluginDefinition()->getRegionNames(), []);
-
+    $regions = [];
     foreach ($this->getComponents() as $component) {
       if ($output = $component->toRenderArray($contexts)) {
         $regions[$component->getRegion()][$component->getUuid()] = $output;
       }
     }
 
-    return $layout->build($regions);
+    return $this->getLayout()->build($regions);
   }
 
   /**
diff --git a/core/modules/layout_builder/src/SectionStorageInterface.php b/core/modules/layout_builder/src/SectionStorageInterface.php
index 13217d82b4..b564793458 100644
--- a/core/modules/layout_builder/src/SectionStorageInterface.php
+++ b/core/modules/layout_builder/src/SectionStorageInterface.php
@@ -18,7 +18,7 @@
    * Gets the layout sections.
    *
    * @return \Drupal\layout_builder\Section[]
-   *   An array of sections.
+   *   An sequentially and numerically keyed array of section objects.
    */
   public function getSections();
 
@@ -61,6 +61,8 @@ public function insertSection($delta, Section $section);
   /**
    * Removes the section at the given delta.
    *
+   * This will re-key every subsequent section.
+   *
    * @param int $delta
    *   The delta of the section.
    *
diff --git a/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderInstallTest.php b/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderInstallTest.php
index 3873af81b0..59ce3535db 100644
--- a/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderInstallTest.php
+++ b/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderInstallTest.php
@@ -2,6 +2,8 @@
 
 namespace Drupal\Tests\layout_builder\Kernel;
 
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
 use Drupal\layout_builder\Section;
 
 /**
@@ -49,6 +51,40 @@ public function testCompatibility() {
     $this->entity->get('layout_builder__layout')->removeSection(0);
     $this->entity->save();
     $this->assertFieldAttributes($this->entity, $expected_fields);
+
+    // Test that adding a new field after Layout Builder has been installed will
+    // add the new field to the default region of the first section.
+    $field_storage = FieldStorageConfig::create([
+      'entity_type' => 'entity_test_base_field_display',
+      'field_name' => 'test_field_display_post_install',
+      'type' => 'text',
+    ]);
+    $field_storage->save();
+    FieldConfig::create([
+      'field_storage' => $field_storage,
+      'bundle' => 'entity_test_base_field_display',
+      'label' => 'FieldConfig with configurable display',
+    ])->save();
+
+    $this->entity = $this->reloadEntity($this->entity);
+    $this->entity->test_field_display_post_install = 'Test string';
+    $this->entity->save();
+
+    $this->display = $this->reloadEntity($this->display);
+    $this->display
+      ->setComponent('test_field_display_post_install', ['region' => 'content', 'weight' => 50])
+      ->save();
+    $new_expected_fields = [
+      'field field--name-name field--type-string field--label-hidden field__item',
+      'field field--name-test-field-display-configurable field--type-boolean field--label-above',
+      'clearfix text-formatted field field--name-test-display-configurable field--type-text field--label-above',
+      'clearfix text-formatted field field--name-test-field-display-post-install field--type-text field--label-above',
+      'clearfix text-formatted field field--name-test-display-non-configurable field--type-text field--label-above',
+      'clearfix text-formatted field field--name-test-display-multiple field--type-text field--label-above',
+    ];
+    $this->assertFieldAttributes($this->entity, $new_expected_fields);
+    $this->assertNotEmpty($this->cssSelect('.layout--onecol'));
+    $this->assertText('Test string');
   }
 
 }