Server thread blocking during login due to synchronous offline permission check

[GenOpenDiesel]

Type of bug

Performance issue or memory leak

/ess dump all output

unnecessary

Error log (if applicable)

No response

Bug description

When a player joins a full server, EssentialsX performs an offline permission check via LuckPerms.
This check blocks the main server thread by calling CompletableFuture.join(), causing noticeable freezes / TPS drops.

Steps to reproduce

Expected behaviour

Offline permission checks should not block the main server thread

Permission resolution should be:

fully async, or

cached, or

skipped on main thread

Actual behaviour

Actual behavior

Main thread blocks during player login

Server freezes are visible when:

server is full

LuckPerms uses MySQL

multiple players join at once

Additional Information

No response

[JRoy]

Need a dump