Is my TMobile sim card incompatible with the Google Pixel3XL?

[Android Central Question]

I just bought an unlocked Google Pixel3XL, unlocked because TMobile is my carrier and only Verizon currently carries the Pixel. Everything works great, except the phone quality. When making calls, the other side is barely audible on my end but you can still faintly hear that the call is through, and the person on the other end hears a lot of cross-talk/interference/noise from my end. I called goodle help and they suggested several trouble-shooting steps including finally doing a complete factory reset and wiping all transferred apps and data. But the problem persists. I am using a TMobile sim card in the phone. Could a damaged sim card be the cause or is it a matter of a TMobile sim card being incompatible with the Google Pixel3XL? Again, calls are successfully going through, it's just that the call quality is very bad. Another peculiar observation, when I make calls after I sync up my Pixel to my car via bluetooth, the calls are fine. Need help.

 

[SpookDroid]

Definitely not the SIM card. This sounds like either a crappy connection or hardware problems, so most likely there might be something wrong with your phone's microphone or antenna, especially since using the same phone but with a BT connection to route call audio/microphone seems to work OK (so the phone is making the connection to the carrier just fine, it just seems that the speaker/microphone isn't working properly).

 

[B. Diddy]

Welcome to Android Central! Are calls fine using speakerphone or a wired or Bluetooth headset?