Some tile entity data not staying synced between server and client

[The_Fireplace]

I have 2 integers, storedFirestarter and storedGunpowder, which are rendered in my tile entity's GUI. When they change on the server, the numbers rendered in the GUI do not change until I save and quit to title and load the world again(I am testing this with a Singleplayer world). I have tried adding the numbers to getDescriptionPacket() then reading them in onDataPacket(), but that didn't work. Here is my code:

TileEntityPopFurnace

https://bitbucket.org/The_Fireplace/unlogic-ii/src/1c46ebb535c1627236380c20291ad45a40ef2f5a/src/main/java/the_fireplace/unlogicii/entity/tile/TileEntityPopFurnace.java?at=master

GuiPopFurnace

https://bitbucket.org/The_Fireplace/unlogic-ii/src/1c46ebb535c1627236380c20291ad45a40ef2f5a/src/main/java/the_fireplace/unlogicii/gui/GuiPopFurnace.java?at=master

Any other code you may need can be found in the repository. Let me know if you have any questions.

[coolAlias]

Whenever any of those numbers change, you need to mark the block for an update so it sends the description packet, otherwise it will not send one until the chunk reloads or some other situation forces it to.