Answer: A: Answer: A: That is normal actions if you are on a call, not using a headset. It is not necessary to lock the phone while on a call, the screen will disable when you put the phone up to your ear.
pressing the side button will hang up on the call! On iPhone 7 Plus and all the other iphones it would lock the phone while keeping the call active. This better be a huge bug. If you are on speakerphone or use headphones or Bluetooth speaker or something like that then it’s supposed to just turn the screen on or off.