diff --git a/core/modules/layout_builder/src/Entity/LayoutBuilderEntityViewDisplay.php b/core/modules/layout_builder/src/Entity/LayoutBuilderEntityViewDisplay.php
index 813b64c8e0..1bb24e07cb 100644
--- a/core/modules/layout_builder/src/Entity/LayoutBuilderEntityViewDisplay.php
+++ b/core/modules/layout_builder/src/Entity/LayoutBuilderEntityViewDisplay.php
@@ -6,6 +6,7 @@
 use Drupal\Core\Entity\Entity\EntityViewDisplay as BaseEntityViewDisplay;
 use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\Entity\FieldableEntityInterface;
+use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Plugin\Context\Context;
 use Drupal\Core\Plugin\Context\ContextDefinition;
 use Drupal\Core\StringTranslation\TranslatableMarkup;
@@ -204,35 +205,7 @@ protected function addSectionField($entity_type_id, $bundle, $field_name) {
    * {@inheritdoc}
    */
   protected function getDefaultRegion() {
-    if (!$this->hasSection(0)) {
-      return parent::getDefaultRegion();
-    }
-
-    $section = $this->getSection(0);
-    return $this->getLayoutDefinition($section->getLayoutId())->getDefaultRegion();
-  }
-
-  /**
-   * Gets a layout definition.
-   *
-   * @param string $layout_id
-   *   The layout ID.
-   *
-   * @return \Drupal\Core\Layout\LayoutDefinition
-   *   The layout definition.
-   */
-  protected function getLayoutDefinition($layout_id) {
-    return $this->layoutPluginManager()->getDefinition($layout_id);
-  }
-
-  /**
-   * Wraps the layout plugin manager.
-   *
-   * @return \Drupal\Core\Layout\LayoutPluginManagerInterface
-   *   The layout plugin manager.
-   */
-  protected function layoutPluginManager() {
-    return \Drupal::service('plugin.manager.core.layout');
+    return $this->getDefaultSection()->getDefaultRegion();
   }
 
   /**
@@ -397,8 +370,12 @@ protected function getRouteParameters() {
    */
   public function onDependencyRemoval(array $dependencies) {
     $return = parent::onDependencyRemoval($dependencies);
-    foreach ($dependencies['config'] as $field_config) {
-      $id = 'field_block:' . $this->getTargetEntityTypeId() . ':' . $field_config->getName();
+    foreach ($dependencies['config'] as $config_entity) {
+      if (!$config_entity instanceof FieldDefinitionInterface) {
+        continue;
+      }
+
+      $id = 'field_block:' . $this->getTargetEntityTypeId() . ':' . $config_entity->getName();
       foreach ($this->getSections() as $delta => $section) {
         foreach ($section->getComponents() as $uuid => $component) {
           if ($component->getPluginId() === $id) {
@@ -428,24 +405,34 @@ public function setComponent($name, array $options = []) {
     // Provide backwards compatibility by converting to a section component.
     $field_definition = $this->getFieldDefinition($name);
     if ($field_definition && $field_definition->isDisplayConfigurable('view') && isset($options['type'])) {
-      if (!$this->hasSection(0)) {
-        $section = new Section('layout_onecol');
-        $this->appendSection($section);
-      }
-      else {
-        $section = $this->getSection(0);
-      }
-
       $configuration = [];
       $configuration['id'] = 'field_block:' . $this->getTargetEntityTypeId() . ':' . $name;
       $configuration['label_display'] = FALSE;
       $keys = array_flip(['type', 'label', 'settings', 'third_party_settings']);
       $configuration['formatter'] = array_intersect_key($options, $keys);
       $configuration['context_mapping']['entity'] = 'layout_builder.entity';
-      $new_component = (new SectionComponent(\Drupal::service('uuid')->generate(), $options['region'], $configuration));
-      $section->appendComponent($new_component);
+
+      $region = isset($options['region']) ? $options['region'] : $this->getDefaultRegion();
+      $new_component = (new SectionComponent(\Drupal::service('uuid')->generate(), $region, $configuration));
+      $this->getDefaultSection()->appendComponent($new_component);
     }
     return $this;
   }
 
+  /**
+   * Gets a default section.
+   *
+   * @return \Drupal\layout_builder\Section
+   *   The default section.
+   */
+  protected function getDefaultSection() {
+    // If no section exists, append a new one.
+    if (!$this->hasSection(0)) {
+      $this->appendSection(new Section('layout_onecol'));
+    }
+
+    // Return the first section.
+    return $this->getSection(0);
+  }
+
 }
diff --git a/core/modules/layout_builder/src/Section.php b/core/modules/layout_builder/src/Section.php
index 20e9dec579..aa103f133f 100644
--- a/core/modules/layout_builder/src/Section.php
+++ b/core/modules/layout_builder/src/Section.php
@@ -132,6 +132,16 @@ public function setLayoutSettings(array $layout_settings) {
     return $this;
   }
 
+  /**
+   * Gets the default region.
+   *
+   * @return string
+   *   The machine-readable name of the default region.
+   */
+  public function getDefaultRegion() {
+    return $this->layoutPluginManager()->getDefinition($this->getLayoutId())->getDefaultRegion();
+  }
+
   /**
    * Returns the components of the section.
    *
diff --git a/core/modules/layout_builder/tests/src/Functional/LayoutSectionTest.php b/core/modules/layout_builder/tests/src/Functional/LayoutSectionTest.php
index 67e8a06e3f..5d3f17d1e0 100644
--- a/core/modules/layout_builder/tests/src/Functional/LayoutSectionTest.php
+++ b/core/modules/layout_builder/tests/src/Functional/LayoutSectionTest.php
@@ -48,6 +48,7 @@ protected function setUp() {
       'configure any layout',
       'administer node display',
       'administer node fields',
+      'administer content types',
     ], 'foobar'));
   }
 
@@ -281,12 +282,14 @@ public function testLayoutUrlNoSectionField() {
    * Tests that deleting a field removes it from the layout.
    */
   public function testLayoutDeletingField() {
+    $assert_session = $this->assertSession();
+
     LayoutBuilderEntityViewDisplay::load('node.bundle_with_section_field.default')
-      ->setComponent('body', ['type' => 'text_default', 'region' => 'content'])
+      ->setComponent('body', ['type' => 'text_default'])
       ->save();
 
     $this->drupalGet('/admin/structure/types/manage/bundle_with_section_field/display-layout/default');
-    $this->assertSession()->statusCodeEquals(200);
+    $assert_session->statusCodeEquals(200);
 
     // Delete the field from both bundles.
     $this->drupalGet('/admin/structure/types/manage/bundle_with_section_field/fields/node.bundle_with_section_field.body/delete');
@@ -295,7 +298,23 @@ public function testLayoutDeletingField() {
     $this->submitForm([], 'Delete');
 
     $this->drupalGet('/admin/structure/types/manage/bundle_with_section_field/display-layout/default');
-    $this->assertSession()->statusCodeEquals(200);
+    $assert_session->statusCodeEquals(200);
+  }
+
+  /**
+   * Tests that deleting a bundle removes the layout.
+   */
+  public function testLayoutDeletingBundle() {
+    $assert_session = $this->assertSession();
+
+    $display = LayoutBuilderEntityViewDisplay::load('node.bundle_with_section_field.default');
+    $this->assertInstanceOf(LayoutBuilderEntityViewDisplay::class, $display);
+
+    $this->drupalPostForm('/admin/structure/types/manage/bundle_with_section_field/delete', [], 'Delete');
+    $assert_session->statusCodeEquals(200);
+
+    $display = LayoutBuilderEntityViewDisplay::load('node.bundle_with_section_field.default');
+    $this->assertNull($display);
   }
 
   /**
diff --git a/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderCompatibilityTestBase.php b/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderCompatibilityTestBase.php
index 5e405bbca0..d5a4cd0b8a 100644
--- a/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderCompatibilityTestBase.php
+++ b/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderCompatibilityTestBase.php
@@ -69,7 +69,7 @@ protected function setUp() {
       'status' => TRUE,
     ]);
     $this->display
-      ->setComponent('test_field_display_configurable', ['region' => 'content', 'weight' => 5])
+      ->setComponent('test_field_display_configurable', ['weight' => 5])
       ->save();
 
     // Create an entity with fields that are configurable and non-configurable.
diff --git a/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderInstallTest.php b/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderInstallTest.php
index 59ce3535db..fa646df1c9 100644
--- a/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderInstallTest.php
+++ b/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderInstallTest.php
@@ -72,7 +72,7 @@ public function testCompatibility() {
 
     $this->display = $this->reloadEntity($this->display);
     $this->display
-      ->setComponent('test_field_display_post_install', ['region' => 'content', 'weight' => 50])
+      ->setComponent('test_field_display_post_install', ['weight' => 50])
       ->save();
     $new_expected_fields = [
       'field field--name-name field--type-string field--label-hidden field__item',