Created attachment 864639 [details]
video of failed login attempts

After boot, or after logout, it's impossible to log in because the password
prompt is closed after a few milliseconds.

 - user clicks on name
 - password / fingerprint prompt appears, but vanishes almost immediately
 - user selection is displayed again

The attached video demonstrates the effect.

The issue "goes a way" after waiting a few minutes. I haven't been able to
figure out exactly when this happens, or what condition needs to be fulfilled
for it to happen.

I have not seen this issue after locking the session, only when creating a new
session.

Note that this bug is *not* about unreliable fingerprint detection; that's also
an issue but I have realized that that's unlikely to be ever solved.

The issue reported here hasn't always been observed. I think I first saw it a
month ago or so. Can't tell exactly.