Why is my Samsung s7 receiving text messages as GROUP text between myself and the sender?

[AC Question]

Every time my fiancé texts me, my new Samsung s7 keeps receiving it as a group text and won't let me keep a conversation (text string) going

 

[Shiitsweak]

Samething happens here.

In the link below. I receive a text from a Samsung user. The yellow bubble is my response. Then again my response shows up in blue.

Whats up with that?