Group Manager Mirroring

I have tried to set it up so that factions has its own group, and that factions_nether, factions_the_end, and a few other worlds are mirrored off of the faction world. For plotworld, I want it to have it's own set of ranks. I have been trying to put plotworld in so that I could add new ranks to that world, but it doesn't seem to want to work. I can't get my Owner prefix to show up. If I go to plotworld and do, /manuadd ronski00 Owner, it says it worked, and I have been moved to the Owner rank in plotworld, but I don't actually get a prefix. Do you have an idea of what could be causing that? Here is my current Group Manager config...

settings:
config:
# With this enabled anyone set as op has full permissions when managing GroupManager
# The user will be able to promote players to the same group or even above.
opOverrides: true

# Default setting for 'mantogglevalidate'
# true will cause GroupManager to attempt name matching by default.
validate_toggle: true
# ************************************************************************************************************************************************************
# *** NOTE: Having this feature enabled can allow improper use of Command Blocks which may lead to undesireable permission changes. You have been warned! ***
# ************************************************************************************************************************************************************
allow_commandblocks: false

data:
save:
# How often GroupManager will save it's data back to groups.yml and users.yml
minutes: 10
# Number of hours to retain backups (plugins/GroupManager/backup)
hours: 24

logging:
# Level of detail GroupManager will use when logging.
# Acceptable entries are - ALL,CONFIG,FINE,FINER,FINEST,INFO,OFF,SEVERE,WARNING
level: INFO

mirrors:
# Worlds listed here have their settings mirrored in their children.
# The first element 'world' is the main worlds name, and is the parent world.
# subsequent elements 'world_nether' and 'world_the_end' are worlds which will use
# the same user/groups files as the parent.
# the element 'all_unnamed_worlds' specifies all worlds that aren't listed, and automatically mirrors them to it's parent.
# Each child world can be configured to mirror the 'groups', 'users' or both files from its parent.
factions:
factions_nether:
- users
- groups
factions_the_end:
- users
- groups
minigames:
- users
- groups
space:
- users
- groups
flat_world:
- users
- groups
plotworld:
# world2: (World2 would have it's own set of user and groups files)
# world3:
# - users (World3 would use the users.yml from world2, but it's own groups.yml)
# world4:
# - groups (World4 would use the groups.yml from world2, but it's own users.yml)
# world5:
# - world6 (this would cause world6 to mirror both files from world5)