This also happen on aaPanel on Debian 12, while Debian 11/Ubuntu 20.04 has no issue.
Solution using "ExecStart=/usr/bin/lxcfs -l /var/lib/lxcfs/" has no effect on Proxmox 8.4.1.
The "top" command report right cpu load, so this issue may not related to LXC, but how Zabbix and aaPanel interact to...