Black Ops II crashes after launch

**Game information**
Black Ops II Multiplayer
Black Ops II Zombies

**Distribution name and version where applicable**
Arch
5.18.9-zen Kernel
Gnome 42.3.1
Nvidia graphics card

**Flatpak info**
Flatpak 1.12.7
nvidia-515-57
default
host

**Problem description**
Game crashed after launch, unhandled exception. (see below)
Valve apparently fixed it with the newest Proton Experimental (or with GE-Proton7-21) but it keeps crashing with the Flatpak version of Steam. I tried it with the native client from Arch repo and it works out of the box. So it seems like there is something missing.

**Does this issue reproduce with native Steam**
No, it does work with the native Steam client.

**Attachments**