PaperMC
Zombified Piglin pathfinding breaks after a short relog
Expected behavior
Zombified piglins should aggro on the player, and then reliably path find towards the player.
Observed/Actual behavior
If you aggro the zombfied piglins on the player they initially path find toward the player, but if you "fast relog" (ie. log out and then straight back in with no delay) then increasing numbers of the piglins will just stand around and do nothing or path find aimlessly.
Steps/models to reproduce
Start the server fresh, log in at the gold farm with no aggro from before, punch a piglin in a boat, get rushed as expected.
Log out and straight back in again, and while some will still try to reach the player, many of the piglins either stand completely idle or move around but are seemingly unable to path find properly to the player. Sometimes this also extends to newly spawned piglins after the relog, but not always (some will path find, some won't). Continuing to attack the piglins does not make them resume normal path finding.
However, logging out for an amount of time that exceeds the delay-chunk-unloads-by value of 10 seconds (ie. just wait for the chunks to fully unload) and then log back in, and behavior returns to normal. Piglins will then immediately resume targeting and pathfinding the player correctly moments after logging back in.
If you "fast relog" at that point, the issue will recur again and has proven to be very repeatable. It's also worth noting that if you bring in a second player while the issue is present, they won't path find towards the second player either so it's not isolated to the original player.
Plugin and Datapack List
Removed everything except vault and floodgate. Same issue.
Paper version
[23:50:54 INFO]: This server is running Paper version 1.21.10-113-main@9fc21bc (2025-11-14T16:11:13Z) (Implementing API version 1.21.10-R0.1-SNAPSHOT) You are running the latest version Previous version: 1.21.10-6e9f5a8 (MC: 1.21.10)
Other
I think the description covers it, but let me know if you need anything else.
Providing this image for context. The mobs in the center made it to the player, and all the other highlighted entities around the middle and edges of the farm are all just standing there idle after triggering the issue with a fast relog.
And then after logging out for 15 seconds, the only mobs that have not moved to the player are just the ones deliberately trapped in boats to help relay aggro through the farm. All of the other mobs are in the kill chamber.