Docker/Portainer in privileged LXC not able to run privileged container?


I have a proxmox server with two fresh Debian 11 LXC container:

Bildschirm­foto 2023-01-28 um 11.59.21
Bildschirm­foto 2023-01-28 um 11.52.37

103/docker2 → is an unprivileged LXC container
104/docker3 → is a privileged LXC container

Now the problem when I try to run a test container in portainer (e.g, ubuntu with console / TTY) and set the “Privileged mode” under runtime and resources the container starts in the 103/docker2 but in the 104/docker3 it throws an error “Request failed with status code 500”?

Both docker and portainer installs done following the official resources, run as root without errors:
Docker Install

Portainer Install

Ideally I need a privileged LXC container because I want to bind NFS shares to the containers in portainer …