Disable MMS/Texting over WiFi

My problem disappeared for almost 8 months, but reappeared last week with a new wrinkle.  This time, I was able to send MMS messages but I couldn't receive them.  Moreover, whereas I got a notification in my messaging app last time I had this problem, I got no notification this time.  I tried rebooting my phone to no avail.  Having no other choice, I decided to call T-Mobile support.

I spent a fair bit of time on the phone with a fairly knowledgeable rep, who took me through a series of steps to fix or at least diagnose the problem, but those steps failed.  He decided to open a ticket on my behalf with T-Mobile's engineering group, and he agreed to get back to me within three business days with their findings.

(The phone started working correctly again later that day and it’s been working fine for over a week.)

Well, he never got back to me, so I called support again and asked them to look up the status of my ticket.  He looked up the ticket and told me the engineering team hadn't done anything yet and forwarded me over to the engineering team.  At that point, I was talking to someone who knew what he was doing.  He told me they had made some changes on "their end" (not to my phone) that corrected the way it was connecting to T-Mo's messaging infrastructure.  He didn't tell me exactly what they did, but he did say that if the problem recurred, I'd need to go into a T-Mo store and either get a new phone or a new SIM card, referencing my ticket number.

I'd suggest that anyone with this problem contact T-Mo support and request that a ticket be opened, and then follow up on it until it gets resolved.  It seems like there is something wrong with the way T-Mo's infrastructure is communicating with certain Android phones.  (This problem has never occurred on my wife's iPhone.)  Mine is a OnePlus 10 Pro 5G, in case that matters.  (I'll never have another OnePlus phone, but that's a topic for another thread…)

Good luck getting this resolved!