I am currently writing a plugin using the CustomBlocksData (https://www.spigotmc.org/threads/custom-block-data-persistentdatacontainer-for-blocks.512422/) plugin to assign persistent data to blocks through chunks' PersistentDataContainers.

The plugin was working perfectly fine, keeping track of data on blocks until recently. Now the data is stored in the persistent data container while the server is online but gets wiped when the server stops or restarts. This happens with saving on stop enabled and happens despite using /save-all before stopping the server.

At first I thought it may have been something I had done, but this issue persists in the bare-bones testing plugin I made. I messaged the author of CustomBlocksData, but he doesn't know what caused the issue either. I remembered I had to install a new version of the spigot server jar recently, so maybe the issue has something to do with that. Thanks!

TEST PLUGIN

Do /test to put a NamespacedKey in the block of the player's location. If the block already has the key when the command is run, a message is sent to the player. Run the command twice to be sure there is a tag on the block. Then, restart the server and run the command again. If there is no message when the command is run the first time, the data did not persist.

Pom.xml: https://paste.md-5.net/uvatakiqum.xml

Main: https://paste.md-5.net/xaxuquxezo.java

TestCommand: https://paste.md-5.net/uvadaxanen.java

Plugin.yml: https://paste.md-5.net/juzodikeyi.makefile