Not sure remotely what's going on a friend bought this unlocked Galaxy Tab A7 Lite "SM-T225" (wifi and cellular model) the model didn't have any carrier branding or carrier, model, and I don't think when I first got this tablet had any [APN] inside it.
MODEL APN issue
The long story short issues started, had a line from t-mobile
(reminder this is an unlocked tablet not a carrier purchase it was direct from Samsung) worked fine loaded it's apn stuff for this network, I got a second phone line from a different carrier which runs AT&T I swapped out my T-Mobile Sim for my AT&T Sim it locked in Tmobiles Apn, I can't delete it, can't reset it, can't add an [APN] says save once I enter the AT&T APN it closes and once I go back to it back to nothing being added, deleted, altered or updated and stuck with T-Mobile....
Is it a Samsung issue or is it T-Mobile locking a unlocked device? Although I purchased it unblocked from Samsung?
I will start with T-Mobile. Not sure why they will lock it unless you bought a T-Mobile compatible device from Samsung. Sure it doesn't boot to magenta flash screen but again, I will start with them as APN settings are carrier dependent/feature.
Right? Yeah it's just a Samsung boot screen, no tmobile software 🤔 very strange I was like we sworn it was labeled unlocked and not the listed carrier ones. Baffled guess I'll have to talk to tmobile.
Right very strange I had a friend who has a pixel 6 pro bought unlocked, put his metro Sim in it and it wouldn't work and he went to metro and they said it "wasn't unlocked and made him pay a fee to activate it" I think tmobile and it's underlings being fishy nowadays.