My LG G3 makes duplicate threads for people, how do I fix it?

[AC Question]

Ok so I woke up this morning (last night it was working fine). Basically I send a text to say a person named "John". John texts back and it makes a new thread in the messaging app called john. If I reply in that new thread I get a error message saying the number is not valid. If I text in the original thread it will send but when "John" replies it makes a whole new thread again, so now I have three threads named john. I checked the phone number and each thread is linked to the same contact, (same number, picture, name, everything). I downloaded a third party messaging app and it is doing the same exact thing. I restarted my phone and it is still doing it.

Anybody have a idea what is happening with my G3, it has never did this before and I updated to lollipop a while ago. My LG g3 is through ATT.