TV QE55Q7FGM not supported any more?

Hello,

I own a Samsung TV QE55Q7FGM but suddenly it is not supported any more by the smart-things app. I re-installed, but it is not even selectable any more.
Is this intentional and is there a way to get the support back? An older version of the smart things app does not help, apparently the list of available devices is downloaded

KB

Does “Suddenly” imply it started this week? If so, ST had an accident earlier in the week where they deleted some hubs and devices from user accounts. If that is the case, you may want to try resetting your TV and try adding it back with the latest app.

Well, my TV was still in the list but appeared offline and would not buck. I then, did, what I always did and removed the device and wanted to add it again. But then the TV does not even appear on the list of selectable TV-sets.
KB