No lte please help! topic

Hi, Im from Mexico and my note 3 uses a 4glte sim card for Telcel company with my plan, its suposed to work the att version here (1700MHz and 2100MHz) but my smartphone only shows "4g" (+HSPA) even in the areas with lte's support. I even tried many things on the hidden menu *#*#4636#*#* but nothing works even if I choose the lte option.

My note 3 info:
SM-N900A
Android 4.4.2
N900AUCUCN2
Custom rom dynamic kat 6.1

Please help me! Greetings from Mexico!