4g not working on iPhone 11 pro max
I have iPhone 11 pro max in which 4g is catching speed only upto 100 kbps and not working fine.I have tried all the steps of the apple support but still nothing is working rather than when i have put my simcard onto another iPhone 8 plus then the internet is catching upto speed of 8.5 mbps.
iPhone 11 Pro Max, iOS 15