Merge remote-tracking branch 'l3/MC-40817' into L3-PR-20210310

Author: veloraven

lib/web/fotorama/fotorama.js

@@ -1903,6 +1903,14 @@ fotoramaVersion = '4.6.4';
             });
         }
 
+        /**
+         * Checks if current media object is YouTube or Vimeo video stream
+         * @returns {boolean}
+         */
+        function isVideo() {
+            return $((that.activeFrame || {}).$stageFrame || {}).hasClass('fotorama-video-container');
+        }
+
         function allowKey(key) {
             return o_keyboard[key];
         }
@@ -3149,8 +3157,7 @@ fotoramaVersion = '4.6.4';
             if (o_allowFullScreen && !that.fullScreen) {
 
                 //check that this is not video
-                var isVideo = $((that.activeFrame || {}).$stageFrame || {}).hasClass('fotorama-video-container');
-                if(isVideo) {
+                if(isVideo()) {
                     return;
                 }
 
@@ -3739,7 +3746,10 @@ fotoramaVersion = '4.6.4';
                 }
 
                 activeIndexes = [];
-                detachFrames(STAGE_FRAME_KEY);
+
+                if (!isVideo()) {
+                    detachFrames(STAGE_FRAME_KEY);
+                }
 
                 reset.ok = true;