BHIM 4.0.3 is here and issue with it persists.
I had written them a mail and today they replied me with this —
We regret to inform you that we are unable to complete your registration on the application, as your device does not meet the security standards mandated by the Reserve Bank of India (RBI).
For your safety and to ensure compliance with regulatory requirements, we request you to attempt registration using a different device that adheres to the necessary security parameters.
We appreciate your understanding and cooperation.
Best regards,
Soujanya
BHIM Support Team.
For the moment I have moved to 4.0.1 which is working fine. I'll keep using It until It completely gives up.
edit: I don't understand why they're not making their app 'BharatOS' compatible ;)