I have 4 TC 85 cameras. All went offline one after the other a couple of days after being updated. They are on a different continent, so there is no way to hard reset. Is there a way to get them back

after all kinds of issues on these shy itty cameras... no having 1 of them again after 11 months completley going nuts. it startet 2 days ago... when the cam suddenly when offline. when i checked it i