Hello, I have been trying to re-format my current permissions using PEX, and setting it so that there are various ranks in different worlds with different rank names per world. I recently finished reformatting them, and the permissions are working. However, every world shares the same rank prefix. I am not sure why this is not working. Here is an example of my current permission file.

groups:
Pluto:
default: true
prefix: '&f[&8&lPluto&f]&7'
options:
rank-ladder: Factions
rank: '1000'
worlds:
Space:
permissions:
- modifyworld.*
Factions:
permissions:
- modifyworld.*
Minigames:
permissions:
- modifyworld.*
Tier1:
default: true
prefix: '&f[&7&lTier 1&f]&7'
options:
rank-ladder: plotworld
rank: '1000'
worlds:
plotworld:
permissions:
- modifyworld.*
Youtube+:
default: true
prefix: '&6&l[&4&lYou&f&ltube&4&l+&6&l]'
options:
rank-ladder: staff
rank: '1000'
worlds:
Space:
permissions:
- modifyworld.*
Factions:
permissions:
- modifyworld.*
Minigames:
permissions:
- modifyworld.*
plotworld:
permissions:
- modifyworld.*

So, I want all users but staff to have separate rank tags with separate permissions in creative than what they have in factions, minigames, and space. Is there something I am doing wrong that anybody can tell? Thanks.