Issue #3227120: Invalidate cache on migration group update

src/Entity/MigrationGroup.php

@@ -2,6 +2,7 @@
 
 namespace Drupal\migrate_plus\Entity;
 
+use Drupal\Core\Cache\Cache;
 use Drupal\Core\Config\Entity\ConfigEntityBase;
 
 /**
@@ -85,4 +86,12 @@ class MigrationGroup extends ConfigEntityBase implements MigrationGroupInterface
     return $this->dependencies;
   }
 
+   /**
+   * {@inheritdoc}
+   */
+  protected function invalidateTagsOnSave($update) {
+    parent::invalidateTagsOnSave($update);
+    Cache::invalidateTags(['migration_plugins']);
+  }
+
 }