Would it be possible when in the HA iOS app you get the message:
–snip
Unexpected frontend version
You are running version 202012051441 of the HACS frontend, but version 20201205162459 was expected, you should clear your browser cache.
–snip
to add a link in the error message to the location in the iOS Home-Assistant app where the frontend cache can be reset? App Configuration > Reset frontend cache. Or just point to it in the error message.