Why do I get two message threads for one group message in iOS 8?
Some iPhone users are reporting a bug in iOS 8 that causes them to receive two messages for one group thread. For example, you have a group titled "Soccer Moms" with six contacts assigned to that group. Five of those user's texts are delivered via the group thread but 1 is delivered via a separate thread / text window. This is just one of many confusing problems plaguing Apple's new iOS 8 group messaging features.