I tried that before and after a restart of the container but the problem is still there.
journalctl -xe shows all kinds of permission problems
Nov 21 05:35:41 mycontainer systemd-udevd[40]: starting version 219
Nov 21 05:35:41 mycontainer systemd-sysctl[41]: Failed to write '0' to '/proc/sys/kernel/yama/ptrace_scope': Permiss
ion denied
Nov 21 05:35:41 mycontainer systemd-sysctl[41]: Failed to write '16' to '/proc/sys/kernel/sysrq': Permission denied
Nov 21 05:35:41 mycontainer systemd-sysctl[41]: Failed to write '1' to '/proc/sys/kernel/core_uses_pid': Permission
denied
Nov 21 05:35:41 mycontainer mount[39]: mount: permission denied
Nov 21 05:35:41 mycontainer systemd-sysctl[41]: Failed to write '1' to '/proc/sys/kernel/kptr_restrict': Permission
denied
Nov 21 05:35:41 mycontainer systemd-sysctl[41]: Failed to write '1' to '/proc/sys/fs/protected_hardlinks': Permissio
n denied
Nov 21 05:35:41 mycontainer systemd-sysctl[41]: Failed to write '1' to '/proc/sys/fs/protected_symlinks': Permission
denied
Nov 21 05:35:41 mycontainer mount[42]: mount: permission denied
Nov 21 05:35:41 mycontainer systemd[1]: Started udev Kernel Device Manager.
-- Subject: Unit systemd-udevd.service has finished start-up