iPhone Xs / Xs max cellular & wifi reception issues

I can forgive the awful names but I haven't been able to live with the wildly inconsistent cellular and WiFi reception issues on the Xs & max. I tried everything I could find to troubleshoot - created separate 2.4 & 5 Ghz bands on my home WiFi, bought a new router, restored from iTunes with no backup, going in and out of airplane mode, etc. - all with no success. Here's what I don't get: even with an extra 4x4 MIMO antenna how awful the reception is. I'll be 10 feet away from my router and the signal completely drops out. Zero connectivity. We don't see these issues on any other device: 7+, 6S, Macbooks, Apple TV, iPads & PC laptops. LTE is spotty in Boston and while I've noticed higher LTE speeds when I have a signal, occasionally I'll have zero connectivity even with a full signal. Going in out of airplane mode has minimal success. The issue only gets worse as LTE signal weakens.

We have an AT&T Xs and Verizon Xs max in the same house both experiencing the exact same behavior on WiFi and LTE. Anyone else have any luck fixing this? Am I missing something? Many have reported identical issues across the web but no response from apple. I know I know, I'm probably holding it wrong. I just hope it's not a hardware flaw.

Visually the new phones are spectacular but are useless if I can trust them to work. We returned ours today. Really hope they fix this soon. For now I'll wait this one out on my 2 year old 7+.