Technical Specs:

• Ma-Enchants-1.15.2-3.1.0
• modpack: Craft to Exile Version 2.5.5gd2
• World Type multiplayer (dedicated sv)
• RAM Allocation 6GB

Describe the bug
While fighting the ender dragon the server just freezes and after 60" the watchdog assumes it crashed and restarts it.

Steps to reproduce the behavior:

1. Go to the end
2. Fight the ender dragon
3. freeze at random moment

Additional Information (screen shots, etc.)
Link to the modpack issue: mahjerion/Craft-to-Exile-Dissonance#109
latest.log -> https://pastebin.com/1hQK2PzQ
crash-report -> https://pastebin.com/sBvHzqmZ

The server does not crash outside the main island where the ender dragon is.
The crash occurs more often wen the dragon is on top of the portal, but also happens when in flight.

Workaround: We did not remove the mod yet cuz it will mess with our current gear, so we fought with unenchanted weapons and it did not crash.

Might be related to #21.