World Containers don't work

[VQ9]

Server Info:

• Server Type: Paper
• Server Version: 1.181
• Java Version: JDK 17
• Online-Mode: True
• BungeeCord: Who uses bungeecord anymore
• Server Logs: That has sensitive information we can't disclose. Working on making that a non-issue.

Plugin Info:

• Version: 1.6.5
• MySQL: No

Describe the bug
World containers don't work.

To Reproduce
Steps to reproduce the behavior:

1. Setup world containers in Bukkit
2. Make a world
3. Watch it not appear
4. It's not appearing

Expected behavior
The world is meant to appear

Plugin List (please provide us with the full list of your plugins)
Nothing which would conflict. It's a private build server.