Issue with Nvidia cards are being discussed on GitHub on proton repository. The only fix at the moment to let it run is to downgrade the Nvidia proprietary driver to 525.
Check out this page of the Arch wiki: https://wiki.archlinux.org/title/Downgrading_packages. The downgrade script in the last section works great. Endeavour OS is Arch-based and uses the same package manager, so it should work. This works only with packages from the official repositories, for AUR packages, you need to downgrade manually.