On your Proxmox host run to see exactly where your driver is being loaded from:
modinfo amdgpu | grep filenameIf it says: /lib/modules/7.x.x-x-pve/kernel/drivers/gpu/drm/amd/amdgpu/amdgpu.ko -> This is the native Proxmox driver. Safe to remove the DKMS packages if installed, if not the skip to point #4.
If it says /updates/dkms/amdgpu.ko, then the DKMS actually loaded, should be rare. Do:
- Remove the Ubuntu DKMS and ROCm apt packages