On May 3, 2019 at 5:15AM I was at the Memphis Airport. My daughter took a picture on her iPhone XS and added it to a long running iMessage thread (using MMS, not iMessage service, i.e. green bubbles).
I didn't get the text. That began a problematic weekend of missing some texts from that thread and, actually, any MMS thread. Sometimes I would get the message. Sometimes not. Sometimes I would get one of several pictures in a message. Sometimes none.
I spoke to a relatively knowledgeable rep at AT&T. He gave me the standard, and probably usually correct, advice of deleting that thread on an iPhone and rebuilding it. That wasn't going to happen. That thread has YEARS of pictures in it.
That was the response I got from Apple several years ago when I couldn't get my number disassociated from iMessage. Eventually something happened at Apple and I started getting messages.
So I was just going to ride it out and hope it fixed itself.
Then during the day on Monday, I got a notification from Essential that the May 2019 update was available. I went to the reddit subreddit to see the comments. Everything seemed good so I planned to apply it that evening.
While I perused that subreddit I came across this thread.
Turns out I wasn't the only one having this problem and it wasn't specific to Essential phones. Here and here are threads on the AT&T forums.
I applied the workaround suggested and all is well.
Obviously this was something that AT&T did in their network, apparently with no regard for non-iPhone users.
This reminded me of the situation back in August 2016. We were in Bar Harbor and Campobello Island and there were plenty of places that didn't have any AT&T coverage. Every time I would enter one of those areas, my BlackBerry PRIV would lose cellular connectivity and then not reconnect until I rebooted. Similar to this week's issue, there was a workaround to change the cellular connection.
BlackBerry finally pushed out a fix for it but AT&T never owned up to what they did.
Then in September 2016 Apple announced the iPhone 7 with an Intel modem.
I suspect that the iPhone 11 is going to only have a Qualcomm modem. Although iPhones have had Qualcomm modems before, since the iPhone 7 Apple has deliberately slowed the Qualcomm modem to be the same speed as the Intel modem.
I'm wondering if since Intel is pulling out of the cellular modem market that Apple is going to let the Qualcomm modem run at native speed in the iPhone 11. And if this is causing AT&T to adjust their network accordingly.
We'll find out in September.