Iphone 16 Airtel user UPI registration failure

I am using Iphone 16 with which i am trying to register For Amazon pay UPI but once the verification sms has been sent and the delivery report has popped up on my screen the amazon app goes to the background getting the registration process killed and amazon asking me to try again eventually ending up with the background app kill and exceeded UPi registration limits for the day. I am an airtel user in India and the same happened with any other upi app. Somebody help me with this