This sounds like a common issue with Nvidia cards and people running dual monitors with different refresh rates.
Here’s a link discussing it https://forums.developer.nvidia.com/t/linux-xorg-multiple-monitors-limits-the-framerate-of-faster-120-144hz-monitors-to-60hz/72083/6
I’ve had it working for months and just today it wouldn’t launch the game from lutris so don’t feel bad. I’m going to give bottles a try tomorrow, but when I get back to the computer I’ll share my settings.