I'm having the same issue as multiple users and I've tried everything, I've been hours changing configurations and I can't solve it.
W11 with official ISO.
cat /sys/module/kvm_intel/parameters/nested
Y
pveversion -v
proxmox-ve: 7.4-1 (running kernel: 5.15.102-1-pve)
pve-manager: 7.4-16...
