[Q] D6603 Can't get T-Mobile LTE topic

I have a shiny new copper Z3 in my hands and today I cut the T-mobile SIM from my Nexus 5 to be able to put in my Z3, however I am not getting LTE at all on it in places that I know it should. Went to the store and they checked the APN and they see no issue. I've downgraded to .93 be able to root, would flashing that FTF interfere with being able to get LTE?