Don’t use X forwarding, have an Xserver running on all gpus
https://forums.developer.nvidia.com/t/unable-to-manually-set-up-fan-speed-overclocking-for-second-gpu-3060ti/175323/2?u=generix
Then correctly use DISPLAY and XAUTHORITY
https://forums.developer.nvidia.com/t/nvidia-settings-unable-to-load-info-from-any-available-system/120192/4