When I was selecting and changing the favorites in my Battlegrounds collection it was like the camera zoomed out and then it looked like this:
I could interact with the buttons like nothing happend but everything was displayed far away. This happend every single time I selected a favorite.
The Hearthstone menu is designed like a box which opens and closes and here it was like I was looking at that open box from above.
This issue did not occur again so far after I restarted the game.
Playing on a PC with Windows 10 on the current patch.