Why is my s6 sending one of my conacts a chat style text message and everyone else sms messages

[AC Question]

Everytime i send a text it is sending it as a "chat", please help get back too sms only

 

[soupadoupa]

My wife is having the same problem with her S7 Edge. When she tries to text me it only gives her the option to send it as chat.

Anybody know how to fix this? I've gone through all of the settings in message+ and don't see anywhere you can set which types of messages to send certain contacts.