Anyone here RMA'd their S10e and saw improvement in reception?

Wife and I upgraded from OnePlus 3t. We use Cricket, which is an AT&T MVNO. Right off the bat, we noticed the reception in our home appears much worse (usually 0-1 bar, -108.0 dBm right now).

It appears like it might be band 12 related, but I am not sure.

Driving around with Android Auto, in urban areas with "excellent" LTE coverage, I regularly notice that the reception icon is crossed out, indicating loss of signal. We never had these problems with the OnePlus 3t on the same network.

It's my understanding that this might be some software issue with the S10s, however, has anyone successfully RMA'd their phone and noticed a drastic improvement? I am willing to jump through the hoops with the warranty process if there is a good chance of this being fixed.

Edit: I also saw some anecdotal "success stories" after users flashed some AT&T image onto their phones. I am skeptical, as I'd rather not flash some firmware hosted on a shady filesharing site, and also don't want to cause any issues with the warranty. I have also not seen anyone presented hard evidence of the AT&T ROM improving actual reception (AT&T might simply be toying with the signal strength graphic for marketing reasons). Not a single post had actual dBm signal strength readings to prove the "improvements". I also saw some comments on XDA saying that the radios are the same between the ROMs anyway.