HUT couch co-op

I am trying to play couch co-op with my girlfriend in hut. I goto single player, exhibition and whenever i try to add friend and she hits confirm on controller it says she needs PSPLUS to play. That doesn't make sense as this is a single player mode AND i can play this mode (which i have done already) by myself (i should note i DO NOT have a PSPLUS account). Please fix this issue and this is one of the 2 modes i purchased the game for. Makes no sense to block out people from enjoying single player fun on the same couch. Also don't forget that offline players would still purchase packs 🙂   I also have a video of the issue if needed. thanks