Is this loss?

No problem, sorry to hear that. If a dummy adapter makes your life easier then that sounds like the best solution. Good luck to you.

Hey, sorry I meant like any Linux distro. Doesn’t have to be Proxmox, but really the point is to see if it happens with another OS because if it does, then it’s likely something with the bios. I mentioned a live distro because you can just put it on a usb, you wouldn’t be commiting to installing it on your hdd/ssd or whatever you’re running Proxmox on now.

Have you tried booting any other distro on there headlessly like a live distro? That may help narrow down if it’s the motherboard/bios or if it’s your Proxmox config