It's normal. Change the APN if it really bugs you.
Hastily spouted for your befuddlement
Hello, I just installed the new OMNIROM 4.4.3 for T0LTE. My SIM is Tmobile and it used to be called Tmobile, but not is being called "US". Is this normal? Any reason why the operator name is no longer Tmobile with this ROM?
Are you talking about the text that is displayed on the lock screen?
Sorry. Should have been "change the build.prop".
Hastily spouted for your befuddlement
Having the same problem, checked in the build.prop, found the one that said US, changed it to T-Mobile, rebooted and still shows US on the lockscreen. Edited the APN settings as well, still shows US. Not that its a big deal, just bugs me a little bit.