Fprintd stalls when tried to unlock the laptop

Fprintd stalls when tried to unlock the laptop. The issue occurs when I follow the sequence.

1. Enroll a finger.
2. lock the laptop.
3. Without hitting any key on the laptop keypad, click mouse buttons.
4. The lock screen doesn't asks for unlock via finger swipe.
5. Forcefully have to enter the password to unlock the laptop.
6. The lock and unlock doesnt work later on, until you reboot the system.

The "mouse click" is the key here. Well I am using a USB based mouse and also I tried the touch mouse on the keypad. I enabled the debug logs for fprintd and found that it fails here. It doesnt even call the "Verify" API.

Device.c _fprint_device_client_vanished "Error closing device after disconnect : The device is still busy with another operation, please try again later. "

Well the FP device is present and intact. So how could this happen?