AirPods Pro are not working for calls

Got a pair of the latest AirPod pro a couple of weeks ago. I was soo excited and wap in proper need for them. But, from the first call I realised that something was wrong - the caller couldn't hear me, the headphones disconnected and was in need for me to manually reconnect them. Or the called couldn't hear me but I could hear them.

Thought to myself 'this must just be a "Monday kind of delivery" the ones that just happened to be a bad batch or something'

Gave them back, apple needed to check if they had the same problem. They did, so i got a new pair.

5 seconds into the first usage I asked a friend to call me - still the same problem.

Tried everything; update, disconnect, reconnect, forget device, delete other apps and so on. Nothing works. So disappointed..

Is there anything else that I can try or is this a constant problem? two of my friends have the same issue