I have a Galaxy J7 Star that I bought off Amazon a couple of years ago. Turns out that it was an unlocked Metro by T-Mobile phone.
Well recently I've been having serious network issues, the symptoms of which included dropped calls, horrible lag before making a call, and more. So I googled how to fix it.
According to this very website, by manually entering T-mobile's APN, I could get my phone off of Metro's APN, and thus resolve some of my terrible network congestion symptoms. So I did that.
Everything seemed fine. However, I could not send or receive MMS messages. I tried tweaking the APN settings in a half dozen ways, and nothing worked. Is this phone blocked from ever sending/receiving MMS messages on anything other than Metro's APN?