Clearly it’s a problem related to the newer versions of ANTI THEFT and not the Android version.
Android phones I have with the old AVAST are still showing up fine.
I got 7 more phones, of which 2 phones which are even turned off for several weeks already, all became greyed-out at the same time in the my-avast interface.
Somebody messed up MY AVAST software as usual (as they did many times before and took ages to fix) and now all we need is the right direct support channel to contact and address this, as seems like these forums are useless when it comes to these kind of issues… :frowning: