Robotic voice on calls with iPhone 15 Pro Max
Found that while on calls I hear the other person like a robot within 10 minutes of a call, and they can hear my voice like a robot too. I took it into the Apple Store since I had AppleCare and it passed the MRI Diagnostic, but they tested the cellular modules in the back it failed, ended up having a mid-system replacement (Same glass, screen, camera, new logic board antennas, interior, and a new battery. It fixed my issue.
iPhone 15 Pro Max, iOS 18