If you have a 2018+ model with T2 security chip or an M-series Mac, then try a DFU firmware Revive to reset the security enclave chip & system firmware.
Also, after deleting all fingerprints, make sure to restart the computer before you add the fingerprints again.
If this does not help, either it is a new bug, or there is a hardware issue with the Mac and the security enclave chip. You can try running the Apple Diagnostics to see if any hardware issues are detected....I'm not sure if the consumer diagnostics will detect a security enclave issue like this though, but an Apple service diagnostic might (Apple or an Apple Authorized Service Provider).
Edit: If you suspect a bug, then you need to contact Apple to make them aware of the issue, otherwise it will never get fixed. You can also provide Apple with product feedback here:
Product Feedback - Apple