I found that the BR matching in the test server is different from the official server (as shown in the picture). Except for BR1 and BR5 which are mixed BR, the others are separate BR. Does this mean the developers want to change the BR matching mechanism? Although I know that the test server cannot match because the version and server are different.
Well, br1 says you’ll match with br1 or br2, and br2 says you’ll match with br2, so…that doesn’t really make sense.
I know, but it is still interesting, isn’t it?
Prolly just a bug. I would love br±0. But this just looks like a bug. You can’t have 1 matchmaking with 2 if 2 can’t matchmake with 1 
Visual bug, there would be a blog about it otherwise
That would be great but of all of them it is BR 1 and 5 that should play same levels.