Description
Stacking prefixes won't work; unable to get more than one prefix to show.
No errors show up

Environment details
Server type/version: Paper 1.16.3
LuckPerms version: v5.1.107

Config

prefix:
  format:
    - "highest_on_track_person"
    - "highest_on_track_staff"
    - "highest_on_track_normal"
  duplicates: first-only
  start-spacer: "★ "
  middle-spacer: " | "
  end-spacer: " "

Editor
https://luckperms.net/editor/B01icB17I2
Chat example.
https://i.imgur.com/eA3Wb4W.png
User Info
https://i.imgur.com/QM7UceP.png

Please follow the issue template.

I suggest you follow the issue template. Include things like screenshot of lp user USER info and as well the web editor link will be good. Also explain how is not working? Errors or not showing in tabs, or not showing in chat.. etc....

Is that better?

Have you restarted the server since updating the config?

Any errors in the console?

The fact that even the start spacer isn't showing is a sign that there is something wrong with your configuration :p