Receiving individual texts as a group message?

[AC Question]

When I get individual text messages from certain people in my contacts (for example, Alisha), it'll show up in my inbox as if it were a group message with other people instead of an individual text from Alisha. I've never started group texts with the other people included so I don't know why it's showing up as a group text. Then if I reply, it replies to everyone instead of just Alisha. If I look at my inbox, the thread only shows Alisha's name, but when I click on the thread, it shows other contacts as well as if it were a group message. The only way I am able to reply to ONLY her is if I compose a completely new message to her, then I am able to have a text convo with her as long as I don't exit the thread. Once I exit the thread, it goes back to looking like a group text when I click back on the thread. I hope this all made sense. Has this happened to anybody else? I don't know how to fix it!