diff --git a/src/Entity/EntitySubqueue.php b/src/Entity/EntitySubqueue.php
index 773f58f3b0ad3268ada5784b4aabf8bfbfa32fd9..932a926c6697ca4204a2eb64013b963f5390a4a1 100644
--- a/src/Entity/EntitySubqueue.php
+++ b/src/Entity/EntitySubqueue.php
@@ -331,7 +331,7 @@ class EntitySubqueue extends EditorialContentEntityBase implements EntitySubqueu
   public function getItemPosition(EntityInterface $entity) {
     $subqueue_items = $this->get('items')->getValue();
     $subqueue_items_ids = array_map(function ($item) {
-      return $item['target_id'];
+      return $item['target_id'] ?? NULL;
     }, $subqueue_items);
 
     return array_search($entity->id(), $subqueue_items_ids);
diff --git a/tests/src/Kernel/EntitySubQueueAPITest.php b/tests/src/Kernel/EntitySubQueueAPITest.php
index 6d1d8a1dc17e8b93a8a07a343433636a3d51cf2e..dfd92690ff4a8241fff4c23bc4a23f0ad065c6c8 100644
--- a/tests/src/Kernel/EntitySubQueueAPITest.php
+++ b/tests/src/Kernel/EntitySubQueueAPITest.php
@@ -58,6 +58,12 @@ class EntitySubQueueAPITest extends EntityKernelTestBase {
 
     $subqueue->addItem($entity)->save();
     $this->assertTrue($subqueue->hasItem($entity));
+
+    // Field widgets append an empty trailing item to the list.
+    // @see https://www.drupal.org/project/entityqueue/issues/3618249
+    $subqueue->get('items')->appendItem();
+    $this->assertTrue($subqueue->hasItem($entity));
+
     $entity->delete();
     $subqueue = EntitySubqueue::load($queue->id());
     $this->assertFalse($subqueue->hasItem($entity));