Item durabilitys are updating very delayed sometimes.

How I tested:

I took some different tools (Pickaxe, Axe, Flint and steel, etc...) and broke blocks or used the tool in a way which would damage it. After I did that, the Item would sometimes take 0.1-1 second to update the durability. 
That is extremely annoying if you are mining and the pickaxe updates delayed while you are already breaking another block and it has to start the breaking animation again.

Tested with:

• With Plugins and without
• Clean Server install
• Latest spigot build
• Different tools
• Different players
• Local Server
• Hosted Server
• Defenetly 20* tps and more then enough RAM

The issue did NOT occur on Vanilla (at least not for me and my friends).

Extra:

/Version: 

This server is running CraftBukkit version git-Spigot-a85f7ec-5870145 (MC: 1.13) (Implementing API version 1.13-R0.1-SNAPSHOT)

I hope i added everything that is needed. If not, please let me know.