Fix issue updating large video 'src' while on stage

modules/UI/videolayout/LargeVideo.js

 
         let container = this.getContainer(this.state);
 
-        container.hide().then(() => {
+        // Include hide()/fadeOut only if we're switching between users
+        let preUpdate;
+        if (this.newStreamData.id != this.id) {
+            preUpdate = container.hide();
+        } else {
+            preUpdate = Promise.resolve();
+        }
+        
+        preUpdate.then(() => {
             let {id, stream, videoType, resolve} = this.newStreamData;
             this.newStreamData = null;
 

modules/UI/videolayout/VideoLayout.js

             this.isLargeContainerTypeVisible(VIDEO_CONTAINER_TYPE)) ||
             pinnedId === resourceJid ||
             (!pinnedId && resourceJid &&
-                currentDominantSpeaker === resourceJid)) {
+                currentDominantSpeaker === resourceJid) ||
+            /* Playback started while we're on the stage - may need to update
+               video source with the new stream */
+            this.isCurrentlyOnLarge(resourceJid)) {
+
             this.updateLargeVideo(resourceJid, true);
         }
     },