Attention: This version will ONLY work on 1.13.2 due to the way that NMS code works, there should be an update soon that will solve this.

Attention #2: I do not plan to update this plugin to 1.14.x until Spigot is no longer in developmental versions.

FIX » Renaming things in anvils should now work properly.
FIX » Items should no longer be "deleted" when closing the anvil.

If you need support, the most optimal way is to open an issue on Github.