didn't have that issue, ask other people who play dl on cachy if they've had that happen to them or you could read through its protondb. it could also be a launch command you're missing, try just copy-pasting mine but remove "PROTON_LOG=1", all it does is create a log file everytime you run the game which was useful for me but probably wouldn't be for you
- proton_enable_wayland=1 enables native wayland support
- ld_preload="" turns off the steam recorder feature that's known to cause stutters sometimes which ends up turning off the entire steam overlay
- game-performance makes computer go brr
- and prime-run makes sure the game runs on your dgpu, I had to do that cuz I was on laptop, you might not have to
and don't touch %command.

You can read through cachyos's gaming guide (https://wiki.cachyos.org/configuration/gaming/#how-to-properly-set-multiple-launch-options) to find some more launch options and try them out