Hi,
The last patch was FP5.UT2P.B.122.20250422, but the Fingerprint reader was mentioned in FP5.UT2L.B.107.20250218. Which are you currently on? List of FP5 software updates here.
Your problem may be a hardware problem.
I would recommend you update to B.122 if you haven’t already. If the Fingerprint reader is still not working, then file a claim under the warranty, best to use the My Fairphone app if you bought your phone from FP, otherwise contact your reseller.