Thank you for the link Eddy !
Ticket opened : #742813 my.avast.com/#devices is displaying “DETAILED INFORMATION FOR DEVICE XXX IS CURRENTLY NOT AVAILABLE” for ALL Android devices since today only (2017/03/09) …

But before your direct link, I could only post to this forum before of … see attached screen capture !
I will inform everyone if I get a solution from Avast support …

Regards
Thierry