Sorry for resurrecting an old thread, but hopefully my solution will be relevant to somebody in the future…
The issue was actually caused by wine/proton not picking the right GPU. Random reboots possibly helped, because GPUs were enumerated in a different order from time to time.
Setting DRI_PRIME and MESA_VK_DEVICE_SELECT environmental variables to vid:pid of the GPU PCI device helped.
To get the id, I ran
$ MESA_VK_DEVICE_SELECT=list vulkaninfo
selectable devices:
GPU 0: 10de:1e87 "NVIDIA GeForce RTX 2080" discrete GPU 0000:01:00.0
GPU 1: 8086:3e98 "Intel(R) UHD Graphics 630 (CFL GT2)" integrated GPU 0000:00:02.0
GPU 2: 10005:0 "llvmpipe (LLVM 19.1.0, 256 bits)" CPU 0000:00:00.0
With vid:pid from the output above 10de:1e87, the variables would be DRI_PRIME=10de:1e87 MESA_VK_DEVICE_SELECT=10de:1e87.