K, here's a stumper that I just can't seem to resolve...
Between my son and myself, both of us having Android devices, I'm on a Note 5 and He's on a Turbo 2. Whenever we're both at home, and he wants to contact from the 1st floor and I'm on the 3rd, he'll often just try to call me instead of yelling or climbing up the stairs to talk to me (don't criticize, I've already addressed that issue and it's unrelated but addressed). 9 times out of 10 I'll answer the phone when he calls, but all is dead silence; I can't hear him, and he can't hear me. After numerous "Hellos?" I'll just give up and go search him out.
However, when one of us is not at home and out and about, we never have that issue. It only seems to happen when we're both in the house.
Initially I thought perhaps it might have something to do with WiFi call settings. I double checked, and both phones do not have WiFi calling enabled. And yet the problem persists.
What gets me, is that it ONLY HAPPENS between the two of us. He has zero issues with anybody else he calls, including his mother who is in the same house (verified that to rule out WiFi calling issues). And it only happens between the two of us when we're both in the house. If I'm out and about away from home, it never happens.
So in a nutshell... it only happens when he calls me when we're both in the house. It doesn't happen for either of us when talking to anybody else. And I've even tested with other people while they're in the house. Now while I bust his chops about "dude, we're both at home, no need to call me, get up on your feet and come talk to me face to face", at the same time, the anomaly has caught my attention, and I'd like to figger it out.
It's actually kinda driving me nuts.
Has anybody else experienced this?
 Oh, and before anybody asks. I've completely hard reset both phones to put them back into their virgin states.