diff -u b/core/modules/text/src/Plugin/Field/FieldType/TextItem.php b/core/modules/text/src/Plugin/Field/FieldType/TextItem.php
--- b/core/modules/text/src/Plugin/Field/FieldType/TextItem.php
+++ b/core/modules/text/src/Plugin/Field/FieldType/TextItem.php
@@ -62,11 +62,7 @@
         'value' => [
           'Length' => [
             'max' => $max_length,
-            'maxMessage' => t('%name: the text may not be longer than @max characters.', [
-              '%name' => $this->getFieldDefinition()
-                ->getLabel(),
-              '@max' => $max_length,
-            ]),
+            'maxMessage' => t('%name: the text may not be longer than @max characters.', ['%name' => $this->getFieldDefinition()->getLabel(), '@max' => $max_length]),
           ],
         ],
       ]);
diff -u b/core/modules/text/src/Plugin/Field/FieldType/TextItemBase.php b/core/modules/text/src/Plugin/Field/FieldType/TextItemBase.php
--- b/core/modules/text/src/Plugin/Field/FieldType/TextItemBase.php
+++ b/core/modules/text/src/Plugin/Field/FieldType/TextItemBase.php
@@ -49,7 +49,7 @@
    * @see static::fieldSettingsForm()
    */
   public static function validateAllowedFormats(array &$element, FormStateInterface $form_state) {
-    $value = array_values(array_filter($element['#value']));
+    $value = array_values(array_filter($form_state->getValue($element['#parents'])));
     $form_state->setValueForElement($element, $value);
   }
 
diff -u b/core/modules/text/tests/src/Functional/TextFieldTest.php b/core/modules/text/tests/src/Functional/TextFieldTest.php
--- b/core/modules/text/tests/src/Functional/TextFieldTest.php
+++ b/core/modules/text/tests/src/Functional/TextFieldTest.php
@@ -170,31 +170,18 @@
   public function testTextfieldWidgetsAllowedFormats() {
     // Create one text format.
     $this->drupalLogin($this->adminUser);
-    $edit = [
+    $format1 = FilterFormat::create([
       'format' => mb_strtolower($this->randomMachineName()),
       'name' => $this->randomMachineName(),
-    ];
-    $this->drupalGet('admin/config/content/formats/add');
-    $this->submitForm($edit, 'Save configuration');
-    filter_formats_reset();
-    /** @var \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager */
-    $entity_type_manager = $this->container->get('entity_type.manager');
-    $filter_format_storage = $entity_type_manager
-      ->getStorage('filter_format');
-    /** @var \Drupal\filter\Entity\FilterFormat $format1 */
-    $format1 = $filter_format_storage->load($edit['format']);
+    ]);
     $format1_id = $format1->id();
 
     // Create a second text format.
-    $edit = [
+    $format2 = FilterFormat::create([
       'format' => mb_strtolower($this->randomMachineName()),
       'name' => $this->randomMachineName(),
-    ];
-    $this->drupalGet('admin/config/content/formats/add');
-    $this->submitForm($edit, 'Save configuration');
-    filter_formats_reset();
-    /** @var \Drupal\filter\Entity\FilterFormat $format2 */
-    $format2 = $filter_format_storage->load($edit['format']);
+    ]);
+    $format1_id = $format1->id();
 
     // Grant access to both formats to the user.
     $roles = $this->webUser->getRoles();
diff -u b/core/modules/text/tests/src/Kernel/TextWithSummaryItemTest.php b/core/modules/text/tests/src/Kernel/TextWithSummaryItemTest.php
--- b/core/modules/text/tests/src/Kernel/TextWithSummaryItemTest.php
+++ b/core/modules/text/tests/src/Kernel/TextWithSummaryItemTest.php
@@ -68,6 +68,15 @@
     $entity->name->value = $this->randomMachineName();
     $entity->save();
 
+    // Test constraint failure.
+    $entity_fail = $storage->create();
+    $entity_fail->summary_field->value = $this->randomMachineName();
+    $entity_fail->summary_field->summary = $this->randomMachineName();
+    $entity_fail->summary_field->format = 'failure_format';
+    $entity_fail->name->value = $this->randomMachineName();
+    $violations = $entity_fail->validate();
+    $this->assertCount(2, $violations);
+
     $entity = $storage->load($entity->id());
     $this->assertInstanceOf(FieldItemListInterface::class, $entity->summary_field);
     $this->assertInstanceOf(FieldItemInterface::class, $entity->summary_field[0]);