When the app started it asked me to sign in (WTF), entered my Microsoft Account (personal, not azure AD) and was meet with the error message: Personal accounts are not supported (WTF).
Utterly useless app at least for accessing on-prem devices on a home network.
I go back to the good old remote desktop app that comes with windows because that is working flawless.
Of course it doesn't work flawless.
If you have been a good boy and followed Microsoft best practice and configured your Microsoft Account to be passwordless account as I have you of course cannot login because, as you would expect, the RDP app doesn't work with passwordless accounts.
It only like 4 - 5 years since Microsoft introduced passwordless accounts so of course that too little time for an organization with 100K+ developers to implement their own best practices in their own products. sigh.