When installing appliance via Script: mount: /oldroot: mount point is busy

Hello, I am tryning to install the appliance to a vps which is running a fresh installed Debian 10.
I am getting the following error

I run the script

wget https://dl3.infscape.com/images/urbackup-app-10-13.sh && bash urbackup-app-10-13.sh

as stated here UrBackup Appliance Download – Infscape Backup Software

and get the following error:

mount: /oldroot: mount point is busy.

I also tried to reinstall the VPS and also tried with a debian 11 instead of debian 10: same error.

I will re-try it on a local debian VM.

Any hints?

OK, my first apptemt was a VPS from dashserv.io
Now when trying on hetzner.com this error doesn’t show up

FYI: and on my Hetzner VPS I had to to a “ifup eth0” after the appliance has been deployed