bro, the reason arena is like the sahara dessert now is because the majority doesnt care anymore .. like the monthly rewards .. you need to get to six path before you can earn the full reward each month or you just get the lowest one, even if you at super kage ... so rather than trying to get to six path .. people just do the training one, and thats only on the weekend ..

dude its not even ranked its training

https://s2.postimg.org/yu0u8yr3t/Untitled-1.jpg

there's a bug there, sometimes i get it too. by refreshing the webpage gets solved.

anyways: when you click on 'training' or 'rank' take a look at the fact if you see only one wheel spinning or if you see the 1st wheel spinning, then, after a very brief waiting time, a second wheel spinning.
if you are in the 1st situation then you got the bug and your arena is not cross server.

This is beyond ridiculous:@

Are you sure the server you are playing at is connected to the Cross server?

In last 100 or so matches I played the waiting didn't go above few seconds.

If so, did you try refreshing the game when the problem started to appear? If the search is at 20 seconds you can instantly assume that it's worth refreshing. If the problem still prevails, again make sure that you are playing on a cross server eligible server, and try again later.

if the timer goes longer than 7-10 minutes leave the queue and either refresh your game or just go in town or something for a second, works for me all the time. Its just a bug that doesnt connect you to the arena.

Now as others pointed out, your server needs to be a few months old to access cross server arena, if your server is too young simply queue with a friend so he can "sandbag" for you and let you win. You will both reach six paths in a few short days.