So I have the same issue. I can get the AirPods to work outside of my house.
In the house they pair easily, work with music, YouTube, etc. However, as soon as I make a call there’s no sound whatsoever. I can see that the Airpods are connected, but I can’t hear the caller and they can’t hear me until I move to iPhone speaker or iPhone.
I can see that there’s some interference at play here, what I can’t understand is how I can do just about everything else with the AirPods except make a bloody call, (which is why I bought them).
Nothing else in my house is effected by interference. I have a Netgear router, Sonos, Firesticks, AppleTVs, Xbox, a plethora of wireless devices connected with no issues - and neither have I had any, why should the AirPods be so sensitive?