Not used Plexamp on my Android phone since the enforced recent password change. it now won’t let me sign in. I can sign in to the main Plex app on my android phone for my own Movies and TV media, but the same username and password says the user isn’t recognised when I try to sign in on Plexamp to access my Music files. Selecting the sign in via browser seems to work in the app but then it shoves me back into Plexamp and it is asking me to sign in and I end up going round in circles!
You can long press the sign in button to send us Plexamp Logs. Not sure what’s up, usually indicative of the lack of ability to find a music library.
