I’m running the following version, which I downloaded the day the September 2020 update came out.
Version: 2.85.681.0 64-bit (September 2020)
I still have the installer file, which I can send you if you want to roll back to this version, since I’ve experienced none of the problems you mentioned.
Rolling back the the September version from Brian didn’t help to resolve the situation. I uninstalled it and went back to the App from the Windows Store and things seem much better now The PBI App required only 2 sign-ins yesterday and so far today none.