Question Player and mob desync after reconnect – entities in wrong position, mobs phasing through walls

[JorgeLOC]

Hi there, I’m running a Paper 1.20.4 server with a large plugin stack (110+ plugins), and I’m facing a major desync issue related to entity positions after a player reconnects.

Issue:
When a player disconnects and reconnects:

• They see other players and mobs in incorrect positions
• Mobs sometimes appear to teleport or phase through walls
• Players appear frozen or stuck to others
• Some movement appears rubberbanded or outdated

Confirmed details:

• TPS is consistently 20.0 (no lag spikes)
• Using Geyser and Floodgate for Bedrock support
• Packet-level plugins: ProtocolLib, Packetevents
• Entity/visual-related plugins: ModelEngine, MythicMobs, Citizens, LibsDisguises, Oraxen, ForcePack, HMCCosmetics
• SkinsRestorer is also active for offline support
• entity-activation-range and entity-tracking-range are set to safe/recommended values in paper.yml

My suspicion:
A conflict between packet manipulation and entity render plugins, or a UUID-related issue between Floodgate and Java/Bedrock hybrid handling during reconnect.


What I’ve tried:

• Reset tracking ranges
• Confirmed it’s not TPS or view-distance

Any help would be really appreciated. I’m open to debugging with test builds or disabling specific plugins if needed. I can provide dump links or logs as required.

Thanks in advance.

Here is a video where you can see the problem

 

[stefvanschie]

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