Disable MMS/Texting over WiFi

Just a quick update, in case anyone is still watching this thread, to note that the problem returned yesterday for me.  I've had to reboot my phone about 10 times between yesterday afternoon and now (5:30 pm local time) in order to send and receive group (MMS) messages.  Until now, I've had no problems for about 6 weeks.

I'm concluding that this is an intermittent issue involving Android phones and some kind of capacity issue with T-Mobile.  Apple phones don't have the problem, probably due to their proprietary way of handling messaging.  Also, this problem only affects MMS messages.  While I'm having problems with MMS, I can happily send and receive SMS messages without difficulty.  I can also make and receive phone calls with no problem.

Another symptom worth noting, perhaps, is when I’m experiencing this problem and someone in a group text sends a message, it comes to me as a text from that person only that can’t be downloaded.