Hi @chaithanya,
After the mTLS connection was successful you should see your device flagged as accepted and not to wait to accept it manually.
I recommend following some double-checking process we describe for troubleshooting.
mTLS is in particular useful in a mass production as it is a secure way of adding new devices to your account without human interaction.
Checking old interactions, I see there is a whole thread in here, how different is your current setup to the one described there?
Regards,
Luis