Just made an account to say that this fixes the exact same issue I’ve had since I started using Tumbleweed a year ago.
Operating System: openSUSE Tumbleweed 20260216
KDE Plasma 6.6.0 (Wayland)
Kernel: 6.18.9-1-default (64-bit)
CPU: 20x 12th Gen Intel Core i7-12700KF
GPU: NVIDIA GeForce RTX 3080
Before running nvidia-smi, only certain versions of Proton (10 or below) would work, applications would not launch or crash on start with errors related to D3D.
After running the command, every version of Proton through Steam and Lutris works fine with zero issues.