iPhone users (and ex-iPhone users) attempting to sign out of Apple’s iMessage service recently began running into a nasty bug. Signing out of iMessage means that iPhones trying to text your number should seamlessly switch back to using SMS. However, this hasn’t been happening lately—instead, these iMessages continue to be sent as iMessages. They never actually make it to their destination, and neither the sender nor the receiver is given any indication that the message has failed.
Hopefully the fix will happen soon.
At the moment, every time my sister sends me a message, I receive it, reply, and then her phone reports her original message didn’t send to me. She’s used to that behaviour now, but it’s odd to say the least.
(And yes, I disconnected iMessages from that number when I switched to Android)