Hi! If you find yourself continually fighting lvl 90s as a lvl 79 please contact customer service directly: Found Here

~Jib

Sometimes for Matsuri it depends on the time of day. If there are not many players available during the time you are playing then after waiting an amount of time, it will match you with any random player that is available. If you can, I recommend doing match making during peak hours so there is a higher volume of players to match against. If you wait until everyone is done or everyone has not started, then you will be matched with whoever is available.

~Jib