Based on what the OP said in the OP and the OP's split level, unRAID is doing what it was told to do. Keeping all folders under Movies and all folders under TV on the same disk.
If that's not what you want then you need to adjust your split level.
i am not sure that is the case. With the given structure a Movie folder or a TV Series folder is contained to a single disk, but new Movies or TV Series folders should be able to go to another disk.
I'm pretty sure it's the case that unRAID is doing that. What I think we need to know is moved the data, because it could have created the folder structure before filing in the movies or TV shows.
I created the Library share, then inside of it I created Movies and TV. I used scp to transfer all the movies from one server to another.