https://bugs.winehq.org/show_bug.cgi?id=46799
--- Comment #2 from Henri Verbeet hverbeet@gmail.com --- (In reply to Zhiyi Zhang from comment #1)
The author said that proton doesn't have this issue. So it feels like the fullscreen hack on proton work around this.
Yes, this happens because of the RandR implementation in the proprietary NVIDIA drivers. There should be a winediag message about this in the terminal.