You can try downgrading qemu as the new qemu 6.1 that has shipped with PVE7.1 maybe what's causing you issues
# Download old qemu
wget http://download.proxmox.com/debian/dists/bullseye/pve-no-subscription/binary-amd64/pve-qemu-kvm_6.0.0-4_amd64.deb
# Install old qemu
dpkg -i...