When I use my AirPods Pro with my iPhone 12 Pro, calls consistently drop within 5-10 minutes. If I call back and use the speaker instead, the call does NOT drop. (No, I’m NOT touching the stems. Yes, I asked this question in an Apple Discussion and the answer was not helpful.)
Does anyone have any idea how to make stable calls while using AirPods Pro?
If you leave the APP in, but set up the call again, does it work? (even if only for another 5-10 min)
I experience something similar where I I start a FaceTime Audio call when I’m walking on the way to work and after ~10 min the connection gets really poor. Audio gets chopped up, the other party claims I drop out or become very faint. I usually can continue on my APP, but I do set up the call again from scratch. It’s very consistent, but so is my route to work. So I’m never quite sure if this is an issue with T-Mobile coverage in that specific location (after 10 min of walking I’m always in roughly the same spot) or if it’s an issue with either FaceTime or with APP that becomes manifest after a certain amount of time. This is the only issue I have with my APP and it’s only on calls. I never experience anything similar using my APP to listen to audio or when using them for example with my Mac for Zoom.
The app I’m using is the standard telephony app, Phone. These are regular cellular voice calls, not voice over IP (VOIP); they do NOT use cellular data. I’m dialing these calls from either the Recents or Favorites tab.
Yes, after a call drops, I’m able to make another call by redialing the number from the Recents tab; the quality of the redialed call is excellent until it drops abruptly a short time later, about 5-10 minutes from connecting.
I do NOT have a problem with disconnecting when I use either of the speakers built into my iPhone 12 Pro, even while sitting in exactly the same location after multiple calls dropped using my AirPods Pro.
I’m running iOS 15.6 and rebooted my iPhone. The AirPods Pro firmware is current, version 4E71.
Is there some way to reset/reboot AirPods?
I’m at my wits end. The current situation is not stable enough to be usable.
UPDATE August 12, 2022
Now I understand 
APP == AirPods Pro
Sorry, I thought it was short for application.
Your AirPod Pros may be eligible for replacement under this program:
I had used my APPs sparingly, but a few months ago, I noticed that they became almost unlistenable after a short period of use. I set up an appointment at my local Apple Store via Apple Support. They took my APPs into the back room, confirmed that they were defective, and gave me a new pair that functions well. Note that only the APPs are replaced, not the case.
Part of my hardware troubleshooting for electronic products is to see if there are any service bulletins or recalls for the product in question.
I read about the program you linked to and it’s about sound issues, not dropping calls.
Nevertheless, I tapped its link, was connected to Apple Support, and (fortunately?) the call dropped while I was talking to the Support person just I told them it would, about 5 minutes after putting on the AirPods. As a result, he arranged for me to bring them in for repair tomorrow at nearby Apple Store.
Thank you for the suggestion. Hopefully they’ll fail at the store too I’ll get them repaired or replaced.
I just got back from my Apple Store.
Their working theory is based on the fact that touching the AirPods Pro stems can disconnect a (cellular) call. They speculate that either (1) the AirPods Pro are sending this signal without the stem being touched, or (2) the iPhone is misinterpreting something in the Bluetooth connection as this signal. In other words, the problem could be either the AirPods Pro or the iPhone.
After looking at and resetting various settings, we tried making a call, but the call did NOT drop after over 6 minutes. They wanted to start mucking around with my iPhone next but I persuaded them to just replace the AirPods (alone, without the case) since they are still under warranty (whereas the iPhone is not).
So, the bottom line is that I’ll charge them up and see whether the problem goes away.
Thank you @aforkosh for suggesting that I take them in.
Wish me luck. 
I had problems getting the new AirPods Pro to connect to my iPhone but that was fixed with a call to Apple Support and resetting them (in the case).
Since then, I’ve had no problems with dropped calls.
I’m having this exact problem with AirPod pros issued as a replacement at the Apple Store from the recall. I didn’t have disconnect issues with the originals, only sound issues. The new ones disconnected at 7min so I went back to apple, they replaced them with a pair that disconnect at 20min.
I’ve made 3 visits to the Apple Store only to have them waste my time. No a “senior advisor” wants me to spend a couple hours on the phone testing my watch, phone and AirPods. I regret purchasing these. I had no issues with the original ones and these are a down grade.