diff --git a/core/lib/Drupal/Core/Entity/EntityForm.php b/core/lib/Drupal/Core/Entity/EntityForm.php
index 301b5ae..b82d283 100644
--- a/core/lib/Drupal/Core/Entity/EntityForm.php
+++ b/core/lib/Drupal/Core/Entity/EntityForm.php
@@ -291,11 +291,18 @@ public function buildEntity(array $form, FormStateInterface $form_state) {
    *   The current state of the form.
    */
   protected function copyFormValuesToEntity(EntityInterface $entity, array $form, FormStateInterface $form_state) {
+    $keys_to_skip = [];
+    if ($this->entity instanceof EntityWithPluginCollectionInterface) {
+      // Do not manually update values represented by plugin collections.
+      $keys_to_skip += array_keys($this->entity->getPluginCollections());
+    }
     // @todo: This relies on a method that only exists for config and content
     //   entities, in a different way. Consider moving this logic to a config
     //   entity specific implementation.
     foreach ($form_state->getValues() as $key => $value) {
-      $entity->set($key, $value);
+      if (!in_array($key, $keys_to_skip)) {
+        $entity->set($key, $value);
+      }
     }
   }
 
diff --git a/core/modules/image/src/Form/ImageStyleEditForm.php b/core/modules/image/src/Form/ImageStyleEditForm.php
index 4edd31c..9c4887c 100644
--- a/core/modules/image/src/Form/ImageStyleEditForm.php
+++ b/core/modules/image/src/Form/ImageStyleEditForm.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\image\Form;
 
-use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Url;
@@ -286,16 +285,4 @@ protected function updateEffectWeights(array $effects) {
     }
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  protected function copyFormValuesToEntity(EntityInterface $entity, array $form, FormStateInterface $form_state) {
-    foreach ($form_state->getValues() as $key => $value) {
-      // Do not copy effects here, see self::updateEffectWeights().
-      if ($key != 'effects') {
-        $entity->set($key, $value);
-      }
-    }
-  }
-
 }