Hi
roykaushik.kr.kr.kr,
Perform below steps:
Update software if not done already.
Check under Safe mode
Run SMMI test to check possible hardware issue
How to Enter SMMI_TEST (test hardware)
Go to Calculator=>type " .12345+= "
you will be entered to SMMI_TEST
Factory reset your phone.
If nothing works, revert back I can take your details and share with service for a check.