Okay a little update.
I tried to tackle this problem again, but today the commands like
smbclient -U alice -L //IP/shares/feedback
as well as others stoped working. I simply get an NT_STATUS_IO_TIMEOUT
Edit:
i checked dpkg -l | grep univention-samba
which returns 3 entries samba4, samba4-sysvol-sync and samba-local-config.
However it seems like port 445 is not listing ?
sudo ss -tulw | grep 445
returns nothing.
I came across this post and therefore tried to check the service.
My service was dead as well.
However, restarting the service didnt helped. 
