iPhone X iPhone network not working right

[Elektrofone]

lately I’ve noticed that my iPhone X doesn’t pick up a signal as well as it used to. Is there a way to determine whether it’s my phone or T-Mobile that’s the problem?

 

[Banglazed]

http://downdetector.com/status/t-mobile/map/

 

[HDFan]

Have you done a network reset on your phone? When I'm having problems a network reset usually fixes the problem. You may have to reenter wifi passwords though.

 

[Elektrofone]

Have you done a network reset on your phone? When I'm having problems a network reset usually fixes the problem. You may have to reenter wifi passwords though.

Yes. I tried that. It’s confusing because there’s no way for me to know if it’s my phone or T-Mobile.

 

[HDFan]

It’s confusing because there’s no way for me to know if it’s my phone or T-Mobile.

I'd vote for T-Mobile as I do see places where the signal is poor, but there's no easy way to prove it. Try it in different locations with different signal strengths. If you know someone else who has a T-Mobile phone see if you get the same results in the same location. Ideally they should have the same phone that you do.