The backup of a CT fails with this:
INFO: starting new backup job: vzdump 300 --mode snapshot --remove 0 --storage Backups_Proxmox --node pve --compress zstd
INFO: Starting Backup of VM 300 (lxc)
INFO: Backup started at 2021-04-16 08:07:24
INFO: status = stopped
INFO: backup mode: stop
INFO...