My main menu screen, i.e., Frozen Throne and any menu where it is running in the background, and maybe some other menus like campaign menus, are running extremely low fps with input lag. Also felt in the Multiplayer chat screen and game creation. Pretty much everywhere that is not actually in-game.
Once in game, the game runs smoothly and I do not have this issue. But as soon as the game ends, and I am back in the menus, it’s back to like 20 fps.
I am on an M1 Mac with the latest Mac OS running a brand new download and install of the game as of last night. No other problems with Blizzard games like WoW or Hearthstone on this Mac.