Recents on multitasking not working properly?

Hello all, so I know that when you text someone or call them they show up on the recents section. It used to be that when you also texted in a group chat, those people in the group would show up in recents as well. Well now when texting in group chat, the recent part has stopped working for me. Its not showing the 2 people in the group that I'm texting in recent section.

Phone: iPhone 6

IOS: 8.4