When I am in a secondary profile and I switch to the owner profile I get prompted for a fingerprint. I place my finger and I am in. So far so good.
When I do the opposite switching from the owner to a secondary user (whoose session is active) I also get prompted for the fingerprint as expected. But there is no reaction to the finger. After several tries I get prompted for the PIN and I can log in.
This is confusing. Best would be if I could switch back by fingerprint. Second best would be a prompt for the PIN.