After you go through a portal (nether portal in my testing, haven't tested end portals) the chunk claims are not loaded for the player.

(meaning players have no indicator of which claims they are in)

@thexaero any update?

I can't work on my mods that much atm because I'm sick.
You can investigate this further for me, if you want to speed things up when I get to this. Try testing in singleplayer and/or without some of your mods.

oh no! I hope you get better soon!

Note the claims disappearing as they are loaded in the map. Exiting and joining back in the server allows the claims to be read as normal.

And please send me the openpartiesandclaims-server.toml config file

Is there anything unusual about the server I should know? This seems to be the only server that is experiencing this.
Please also tell me your Minecraft, mod, Forge/Fabric/NeoForge versions.

openpartiesandclaims-server.txt
File type is changed in .txt so that I could have it here

• 1.20.6
• Latest version of Fabric
• Mods:
  

Thanks! I'll look into it.

When you talk about going through the Nether portal, you mean the vanilla function of the Nether portal? Going in the Nether? Are claims unloaded in the Nether as well?

Yes, and yes

Alright, seems like Fabric started handling packets in a scheduled main thread task with 1.20.6, affecting the order in which some packets are handled in relation to vanilla ones. This made the client mistakenly assume that the server doesn't have OPAC installed. Seems very easy to fix the issue though.

Oh wow, it's not even a compatibility issue with another mod. I was just able to reproduce this. Weird how nobody else is reporting the issue.