Why can't I find a match?

I got a mission for 2 wins in a duel, but there's no opponent. After watching an ad and changing it, I got a mission for 3 wins in a duel 18. Annoyed, I watched another ad and rerolled, and now it's asking me to use a mystery item in a duel. Are they telling me to do it alone even if there's no opponent? Damn it.