have a 8.x PVe installed from a 8.x installer, My sources.list shows
deb http://ftp.de.debian.org/debian bookworm main contrib
deb http://ftp.de.debian.org/debian bookworm-updates main contrib
# security updates
deb http://security.debian.org bookworm-security main contrib
deb http://download.proxmox.com/debian/pve bookworm pve-no-subscription
deb http://ftp.de.debian.org/debian bookworm main contrib
deb http://ftp.de.debian.org/debian bookworm-updates main contrib
# security updates
deb http://security.debian.org bookworm-security main contrib
deb http://download.proxmox.com/debian/pve bookworm pve-no-subscription