The specs identify this as the SM-G892A - the model made for AT&T. That would make it the model that does not have support for LTE Band 71, the 600MHz network TMobile has deployed. (It supports every other LTE band that TMobile uses, though, so it’ll still work; it just wouldn’t work as well. Most likely you’d have occasional potential problems when in buildings; depends on where you are.)
All Snapdragon S8 work on every US between. GSM and CDMA. Firmware is the only difference. They stew all hardware identical. If it’s unlocked it will work. I personally flash U1 for international firmware.
Thank you for helping me understand what the problem is. A small amount of that was over my sometimes electronics inept head. LOL However, your explanation was great so I got most of it. Certainly enough to understand the points. I really appreciate it. I have had many cell phones and carriers through the years. (back to the bag phone days if that tells you anything). I have never had a phone that would consistently work inside my house until I found out about WIFI calling. That was an incredible feature for me on my previous phones. It is sad that this phone will not support WIFI feature because I love everything else about it, At least now I know what the problem is so I won’t be frustrated and confused. Thank you again for spending the time to help me.
Thank you for your advice. I appreciate you taking the time to help me. I was with you (meaning: sort of understood ) until the last sentence. Could I impose upon you for help understanding what that means. I am afraid that I am not all that electronics literate. Thank you.