This started a few days ago. I've been getting texts from friends with iPhones in the wrong order, and seemingly they are getting mine late. So I texted a friend whose grandmother was in the hospital yesterday, and her conversation with me looked like this. These texts from her arrived around a minute apart each. I think the intended order of them is fairly obvious. It's worth noting that every time I send her a text, the read receipt line under the text shows a little clock for a few seconds or more, which I think means it hasn't been recieved by her phone yet. Also worth noting that I had a conversation using the same stock messaging app with my mom yesterday who has an android and I don't think we had any such issue, but that may have actually been RCS.
Anyway, here's the example. It's not the only example I've had with her or with another iPhone-using friend in the past couple days.
Me: Hey, how's your day? Any updates about your grandma?
Her (a few hours later): I feel relieved
Me: does that mean you got good news?
Her: how was your day?
Her: yeah
Me: my day was good, (proceeds to describe what I did that day)
Her: my family feels relieved too
Me: what was the good news? Your grandma is okay?
Her: Hey $bionicjoey, I didn't get much sleep last night but I just heard that the doctors say my grandma is out of danger.
Edit: I texted her last night saying something weird was going on after that exchange, and then this morning at about 7:30 AM I texted her saying "let me know as soon as you get this". She just texted me at 2:30pm saying "I just am just now seeing your texts"
So it might not even be my personal carrier, it might be some lower level carrier that my carrier is connected to.... That's annoying.