My friend hosts a realms server that runs on 1.14.4 and whenever i try to open a chest that would contain a treasure map. Most of the time this crashes the server, one time i was able to see that the chest contained a treasure map.
Steps to reproduce.
Find a shipwreck
Open all the chests (it's usually the one in the cabin i think)
Crash the server.
Linked issues
Comments

I have exactly the same on my 1.14.4 map.
I discovered this in multiple ships.
It seems that there is an issue qhen createing the trasure map. Because even when you are able to open the chest,m the trasure map is missing, but It should have a 100% dropchance.
We discovered, that you can prevent server crash when setting