I am experiencing the same problems and have noticed that after a reset, the AirPods Pro only work properly for 2 times and then show the same problem again. This indicates that the problem must be solvable and therefore I would like to do my best to describe the problem in as much detail as possible so that Apple support can do something with it.
Problem description:
When making outgoing calls, I give the command "Hey Siri, call Peter". Siri confirms via the earpods that the iPhone is going to call Peter. So at that moment there is a direct working connection between AirPods and iPhone. The iPhone starts calling and I hear the usual outgoing call tone. I also see the orange dot turn on in the top right corner of my screen, indicating that the microphone on my AirPods is also activated. At the moment that Peter picks up the call, I see;
- The orange dot goes out;
- my iPhone displays the icon indicating that sound is coming through my AirPods even though I can't hear anything on my AirPods.
It then takes 4, 8, 12 or sometimes 18 seconds before the orange dot on my iPhone comes on and the sound on my AirPods is activated. Peter did not hear anything at all during that time, which indicates that the phone connection was established correctly, but that the connection between iPhone and AirPods did not work.
I also have the same problem with incoming phone calls.
Was this problem present from the beginning? No, but unfortunately I cannot remember when it started. However, I suspect that this problem is related to the fact that I also have an iMac, MacBook and iPad in my house. The AirPods Pro bluetooth profile is apparently synchronized on all my devices via iCloud. It seems that when the sound of the phone call starts, the AirPods first check to see if they should accept the sound from the iPhone. As if the sound of the phone call comes from a "new" source. I guess that the length of the time out seems to be related to the number of other Apple devices that are near my AirPods Pro.