I think my Galaxy A50 device is unlocked by unregistered fingerprint. Why is this

A: Sorry for your inconvenience.
Samsung is aware that some Galaxy A50 users may experience this under specific circumstance.
Recently Samsung had known that Blue Light Filter of high level can affect to fingerprint recognition algorithm.

This issue has already been resolved with a software update which will be available in the upcoming days.

Therefore, please check for updates to your device SW regularly via the FOTA or Smart Switch PC.
Samsung encourages users to keep your software and apps updated to latest version.

Please delete existing registered fingerprint and deactivate Blue Light Filter feature until new maintenance software will be released.

After updating to new software, delete registered existing fingerprint as well and register new fingerprint.

Even though you had unlocked device by only pattern not fingerprint, you have to delete registered  existing pattern and register again for enhanced security after software update.

Samsung is committed to providing the best possible mobile experience to customers.