Crashes in instancing

[prebaked]

Current Behavior

Server crashes when a player logs out or dies inside of an instance after a few server cycles.

Expected Behavior

Player should be able to log out and either be teleported to instance exit tile or the instance state should be preserved.

Steps to Reproduce the Problem

1. Enter instance
2. Log out or die in instance

[Tomm0017]

Was not able to replicate this issue

https://i.imgur.com/gpz9PBw.gifv

[dosier]

I did experience this issue with the following (test) plugin @Tomm0017 :
https://paste.ofcode.org/L6RBWiS4EacUYySANia44a

Simply execute the command ::poh twice and wait a short period of time, the client will stop responding and soon log you out. Note that the command accepts three parameters, I am fairly sure that what is entered here is irrelevant for the problem to occur. So entering

::poh 0 0 0

three times should suffice.

[dosier]

I ran some code to print out the exact coordinates of the instance for each height level
results:
https://paste.ofcode.org/vZ2UhrN3bvMYSsPz3QKBVv
These are prints of a 13x13 matrix of chunks for a specific height level
If anyone is interested in the code to generate it:
https://paste.ofcode.org/89MifdYN6yHnwnzwndf6i9
(Would be nice if we could instantiate a new world without all the config stuff btw, for test runs)