I don't know why my text app is splitting my text conversation.

[Blazebullet]

so i just got back from mexico, was using hangouts instead of my normal text app. Now my frequently text contacts conversation threads have the area code of mexico for some reason. I go into contacts but it doesn't have mexico's area code.
ex.) my girlfriends thread has a ton of message in it, now as i am home, she texted me and it started a brand new separate conversation thread with her phone number as it should be. the previous conversation changed with mexico area code and i can't seem to change this.

Any help is appreciated and I have tried many things already and open to suggestion.

 

[B. Diddy]

Welcome to Android Central! Sorry, can you clarify -- are you talking about SMS messages using the stock Messaging app, or are you talking about Hangouts (which, as you probably know, can't be used for SMS).

 

[Rukbat]

Or Hangouts dialer, which can be?

 

[B. Diddy]

Or Hangouts dialer, which can be?

Are you saying Hangouts Dialer can be used for SMS?

 

[Rukbat]

I do it all the time, on the phone and on the PC with the dialer add-on in Firefox. MMS too, if I paste in a picture.