There was actually one method that broke in 1.20.5. I believe it's the first time this happened on the free version of PvPManager.
It's solved with this update, you might need to change some potion names in the config potion list or delete it and let it regenerate.

Changelog:

• Added support for Minecraft 1.20.5
• Some new message translations from crowdin
• Updated a few libraries

If you are satisfied with recent updates, I would appreciate it if you left a nice review.

For some extra features/updates check out PvPManager premium