@Ipool: Well, a downgrade (uninstalling the update) of Andriod TV Home (= Android TV start page) helped me, from version 3.3.5 to 2.1.3.
Important: Deactivate* the automatic updates on Box and Google Play and, of course, do NOT update Andriod TV Home any more. But then you have to update the box manually.
By the way, this is why it has a lot of 1-star ratings on
https://play.google.com/store...Users are complaining in droves, but Google (and Nvidia) probably don't give a shit :(