Employee Checkins are getting updated automatically everytime

We have deployed ERPNext in client local Server Computer, to help get the checkins from biometric devices using the auto-attendance-biomteric-tool python script.
We are observing the SHift Types are getting updated automatically everytime even if checkins are not coming everytime. Checkins are coming as employees are punching on the biometric devices, but the SHift Types are getting updated everytime automatically.

Kindly advise.
Thanks in adv.