While opening the camera from inside Instagram my phone crashed and i had to reboot it. But after the first reboot the fingerprint sensor seemed to be not working. After that I restarted the device again but it again failed to recognize any saved fingerprints on the lock screen.The sensor seemed to work fine as I was able to add a fingerprint but it failed to unlock the device/ unlock Tez. After this I had to add fingerprints again and a little while later everything was back to normal.
This might be a small software bug but I'm just putting it out there for anyone who's listening.