Sprint S8 poor reception and/or mic issues

I have a Samsung Galaxy S8 on Sprint network. Bought in July/2017 and has worked excellently until a month or so ago. I can make/receive calls, but for some reason folks on other end of call keep saying I'm breaking up, cutting out, or just can't hear me.

I have booted to Safe Mode & tried; same issue. Cleared/cleaned cache;same issue. Turned off Bluetooth;same issue. Does the same on speaker, headset or with phone to ear. Issue is not specific to one area, it does pretty much anywhere I go. Sprint tower 3 blocks away from home; and yes, it definitely does it at home too. UGH!!!!!

Anybody got any advice and/or fix???