Hi guys,
I hope I can help someone out there regardless of the fact that I use SONY WH-1000XM4 BT-headphones instead of "ApplePods"; but do think perhaps that the source of the problem can be the same:
The symptom is that if I answer the incoming call with the green call button on my watch the call is not routed to the watch > headphones. I noticed that if I keep the call active, and click on the phone top left corner "call symbol" the call suddenly WAS routed to my headphones as expected. So I thought it had to do with some background app issues on the phone.
Today I experienced many weird issues with my BT-headphones and googled how to reset them. I held CUSTOM button + Power button in for 10 seconds while it was off, and connected to a power source. Then I did the same while off while NOT connected to a power source to delete any presets.
Then I paired them FIRST with my watch (Bluetooth), and then paired them with the phone.
My wife called just now, and guess what - I answered on my watch (green button) and the call was routed to my headphones. Seems like it is working now.
Perhaps this might be the same for any BT device? Try to completely reset them, and try to pair them FIRST to the watch and then to the phone. I don't know if that is how it is done with ApplePods but perhaps then I can help someone else out there with a different BT setup like me (Sony).
I suspect that the pairing order can "trigger the bug" in iOS. Apple will probably fix this later on if my theory is true.
Peace.