OBirder
macrumors 6502
I'm having the exact same issue. I have 7 plus. Apple replaced both AirPods and case last week however the issue still persists. Please keep us updated. They're great for listening to music but it's a total crapshoot if they're going to work for a call.
I have the 7 plus and original Apple Watch. I don't experience this. Had calls for 3 hours and didn't disconnect.
Only disconnects when I get into my car and my phone connects to the car Bluetooth.
At times it might take a while to switch if I was connected to a different device. In some rare cases I had to reboot.