Okay Chuck, looks like I found an (possible) solution to my and maybe also reap AND HaNeTheBerG problems.
Since we all (me included) use a new router (Fritzbox) it looks like we have to reopen the required ports again (see solution here: Agents are not working on my PMS on NAS)
I will check tonight, if this solves the problem.
Thanks for your help anyway!!
