bayerelm
I had the same problem and because my three apps, which actually require Google Play services, now run quite well without Google Play services, I had deleted the user profile I had created for this purpose.
I have just created a "Google profile" for testing purposes and saved a fingerprint.
Now everything works as expected!
After the first change, there was a brief problem as described by one of you (fingerprint symbol only appears very briefly, then GOS wants the password again).
But since then, the lock symbol changes to the fingerprint symbol after two seconds at the latest every time the profile is changed and logging in then really works.
However, I have now only stored one fingerprint in the second profile.
There was (is?) the other problem that the second/each additional profile cannot remember more than one fingerprint.
I will test whether this problem has been solved later.