Hey @Thomas_Pluemper – thanks for all these details, and sorry for the trouble here.
What happens if you temporarily run the Roon Core elsewhere, like a laptop or desktop computer? If that works, we’ll know more about the issue, so it would be great if you could try that test for us.
All you’ll need to do on any Windows or Mac device with Roon is go to Settings, click Disconnect, and then choose Setup Roon Core On This PC/Mac. Let us know how that goes, and I’m sure we’ll be able to figure this out.
many thanks for your quick response and a happy 2019 to you (and the Roonies).
I have solved the problem in the meantime. I replaced the router by an older one which I had lying around. This solved the problem, but I did not like that solution. Nevertheless, the router-Tidal connection seems to be the problem. I then changed the setting of my standard router to allow for DDNS using 8.8.8.8 as address. Now it works - at least for the time being. Let’s see whether it keeps working through 2019.