Displaymodeselector set mode to graphic then DP no output

I have a RTX A5000 card and try to install vGPU driver on Proxmox 8.3. I have set mode to compute, but I have never get vGPUs successfully. so I decided to reset display mode to graphic and reinstall proxmox 8.3.

But when I use “displaymodeselector --gpumode graphic --auto”, everything seems okay,
“displaymodeselector --listgpumodes” I got “GPU Mode: Graphics”
but the Graphic vard DO NOT OUTPUT sinals to display.

Does anybody met this problem?
How can I get my A5000 card to act as a graphic card again?
Thanks