iPhone 14 pro max bug. (music)

Hi, I'm an iPhone 14 Pro Max user. Recently, I found a bug in iOS 15.4.1. When I connected my device to my car stereo to hear music, I got a call in the middle of it. Then, I picked up the call and changed the speaker from Bluetooth to my iPhone's speaker. But I found that during the call, the music didn't stop. It was working along with the call. Moreover, I tried this same thing again to confirm, and I found that this bug happens in this same circumstance. Does anybody have this problem? Do you know how to report bugs on the iPhone? To let them know the developers.