Same here with a FP3+, /e/OS 3.1.4, N26 version 4.36
I did an experiment on an stock android and the N26 app request now to enable biometric face recognition, after taking a photo, I could go forward and see my account details.
Seems that biometric face recognition is new since some days. N26 version 4.34 and 4.33 do not work neither.