I would recommend Nobara, which has a Nvidia-specific installation and comes from Glorious Eggroll (the GE in GE-Proton). Bazzite is also a fine choice. Both are based on Fedora.

I wouldn’t choose Debian for gaming if you can help it - Debian chooses stability instead of gaming as focus, which is fine for servers, but not for your usecase.

But to be honest, I don’t think openSuse is the reason for your issues - the probability is high that it’s an issue with Proton or the Nvidia drivers. Try posting logfiles!