Updated in videolayout

modules/UI/videolayout/LargeVideoManager.js

             show = APP.conference.isConnectionInterrupted();
         }
 
+        let id = 'localConnectionMessage';
         if (show) {
+            UIUtil.showElement(id);
             // Avatar message conflicts with 'videoConnectionMessage',
             // so it must be hidden
             this.showRemoteConnectionMessage(false);
+        } else {
+            UIUtil.hideElement(id);
         }
-
-        document.querySelector('#localConnectionMessage')
-                .classList.toggle('hide', !show);
     }
 
     /**

modules/UI/videolayout/VideoLayout.js

      * video stream is currently HD.
      */
     updateResolutionLabel(isResolutionHD) {
-        document.querySelector('#videoResolutionLabel')
-                .classList.toggle('show', isResolutionHD);
+        let id = 'videoResolutionLabel';
+
+        if (isResolutionHD) {
+            UIUtil.showElement(id);
+        } else {
+            UIUtil.hideElement(id);
+        }
     },
 
     /**