Why would I receive a red exclamation mark notification when a text comes through?

[kxtat]

I have a Samsung Core Prime. I do not have this contact set as high priority, and the red notification only pops when I get a text from them. Why?

 

[srkmagnus]

I have a Samsung Core Prime. I do not have this contact set as high priority, and the red notification only pops when I get a text from them. Why?

Perhaps that person is sending you a text message with high importance and is the one flagging it?