Google account remains stored after deletion and 2FA account is not working

I added two Google accounts via microG on Android 10, the second one needed 2FA but didn't come up as available account in the Google Drive app. So I removed both Google accounts, deleting and reinstalling the Google Drive application but although there was no Google account on the device anymore, the first Google account icon still came up in the Drive application without any functionality. I added the second Google account with 2FA again, that appeared as icon after wiping the app data but documents did not load. I added a third Google account without 2FA and got two accounts, the first one that is still stored somewhere although not listed under "accounts" in Android and the third without 2FA which is accessible in Drive.

Therefore, there is
a) a bug storing deleted Google account data somewhere on the device
b) currently no chance to use a Google account with 2-factor authentication under microG

Please see the files attached and fix both issues.

bugreport-J9210_EEA-55.1.A.3.49-2020-03-20.zip

Start by reviewing the attached bug report and screenshots, then reproduce the account-removal and 2FA scenarios on Android 10 with Google Drive. Trace where microG account data and 2FA authentication state are handled. Done means deleted accounts no longer appear in Drive and a 2FA account can be added and load documents.