Originally Posted by
MorgenBlue sm2g900tzkaatt
That shows the phone as having an AT&T Product Code originally.
Since the Latin America, G900M, and the T-Mobile (USA), G900T, and the AT&T model, G900A, are all interchangeable and the firmware, "Version", details are a mish-mash of all three... I would suggest flashing a stock, unbranded firmware for the Latin America model. The reasoning behind this is that the T-Mobile (USA) firmware will be carrier branded and the latest AT&T firmware is not released by them. So, I suggest the Argentina, stock unbranded, Samsung firmware for Android 6.0.1, Marshmallow...
Model SM-G900M
Model name GALAXY S5
Country Argentina
Version Android 6.0.1
Changelist 110166628
Build date Wed, 23 Mar 2016 18:55:40 +0000
Product code ARO
PDA G900MUBU1CPC4
CSC G900MUUB1CPC4