do ls -la on /var/lib/lxcfs/cgroup/memory/user.slice/user-0.slice/session-22.scope/memory.force_empty to see your permissions.
but it told you for reading
anyway need reboot the node
1- after upgrade from PVE5 to PVE6 (that is really important)
2- after renew certs
after reboot see what say systemctl status pveproxy.service ?
what is your PVE version?
this post maybe helpful
https://forum.proxmox.com/threads/proxmox-6-1-7-pct-restore-unable-to-parse-volume-id.67076/#post-301172