Nello Lucchesi Said:
"iPhone Drops Calls While Using AirPods: 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.) Does anyone have any idea how to make stable calls while using AirPods Pro?"
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It may be the iPhone, and not the AirPods. So, troubleshoot the iPhone...
Troubleshooting Dropping Calls:
A. Install a Cellular Update:
It might be prompting you for a cellular update to install. So, go here for that. Update your carrier settings manually on your iPhone or iPad - Apple Support
Also...
B. "No Service":
Is "No Service" shown on the top-left corner of your screen? If so, go here to fix that: If you See No Service or Searching on your iPhone or iPad - Apple Support
No Success?...
C. Whom to Contact:
Contact your Carrier, as they are the one who provide you with the service of Cellular and Voicemail.