When my iphone calls someone, it just reminds me that the other person is on the phone. ...

Are you sure the other party is on the phone? Is everyone like this? A common problem with iphone calls should be to ring twice and then show that the call failed. If she is the only one, is there a do not disturb time setting on the other party's mobile phone? Another tragedy may be that there is something wrong with her cell phone signal. I also called my classmate before. After the signal was bad, he connected the phone and was making a phone call.

It doesn't mean that there is no signal problem when you receive SMS normally. Simply put, the call is the stability of the continuous signal, and the short message is OK as long as there is an instantaneous signal.