Um.... that's how it works. Once you hit 6P you can't match anyone not 6P. Queue times increase noticeably after that because the exact matching depends on matching other 6P people. I've waited 2+ hours before for a ranked match. Same reason why when you look at Rankings, most people in Ranked Arena rarely go that far past the minimum requirement. No one wants to wait hours for a match after that.

It's also done like that so someone can't hit 6P then just give away wins constantly to people.


The only real exception to this is Theme Arena, which doesn't follow the same rules.