Mini Games - Can't Choose an Opponent

I've recently been trying the mini games out for some additional practice. I've noticed that I can't choose an opponent in the mini games. So in the mini games, when you get to the team select screen, I can select the team I want to play with, but I can't select the team I want to play against. The only way that I have found to select another team is to leave the gamemode and then re-join.

So I'm not sure if this is a bug or not. If it is a bug, I'm happy to describe if it there's a form to report bugs. Has anyone else experienced this?