Not sure if anyone here is running on linux but I had the same problem and figured out a solution.
Just wanted to say i've been trying to fix bg3 freezing on 100% for several days now.
TLDR: flatpak update
I run on pop_os! with steam and proton
I'd tried numerous (increasingly reckless) fixes I'd found online including running vulkan, skipping launcher, reinstalling nvidia driver, system updates, uninstalling and reinstalling wine (to run with lutris), removing patch 3 and 4 files and other bg3 file manipulations.
I was just about to reinstall bg3, then steam, then test with lutris. When I finally fixed it by updating my flatpaks.
Now to see if this has fixed dota2.
I hope this helps.
