I'm planning to buy the Iphone 8 64gb model a1905 for my AT&T carrier. But on the description for the phone it says it's for Tmobile only on ebay. I know the A1905 is for all GSM, does this mean the A1905 model phone will work on AT&T even though it's a Tmobile phone? please let me know before I make my purchase and thank you guys for your help.