No more shell or ssh after installing PBS within LXC

[whostolemyname]

Hello everyone,
today I tried to install a Proxmox Backup Server inside a LXC container, since I have only one singele NVMe in my server running PROXMOX VE. I've mainly been following two different approaches from tutorials on the web:

1. https://www.jdbnet.co.uk/post/install-proxmox-backup-server-4-in-an-lxc-container
2. https://www.youtube.com/watch?v=sOUgzPocqFM

Both result in not beeing able to accessing the LXC's console in Proxmox VE or being able to ssh into the LXC from a terminal. After having encountered this behaviour I took snapshots of the container to verify that this behaviour occurs only after installing Proxmox Backup Server.
So far I didn't find any useful information "googling" this behaviour. On rebooting the LXC, the log states an error, which is mysterious to me: command '/usr/bin/termproxy 5900 --path /vms/220 --perm VM.Console -- /usr/bin/dtach -A /var/run/dtach/vzctlconsole220 -r winch -z lxc-console -n 220 -e -1' failed: exit code 1

Has anyone encountered a similar phenomenon?