Reproduction steps:

1. Hold onto an item.
2. Rename the item using a plugin.
   The item will take a good ~0.5-1 seconds for its name to change. It is supposed to be instant.

This problem only started when I upgraded from a version (it says unknown-unknown in the logs, unfortunately) that I built with BuildTools on the 2nd of January 2015. Renaming items have always updated their names instantly.

Do you have any idea what changes were made to have created this delay? I am capable of fixing the problem myself, but I was hoping I could get some guidance.

Thank you for any help you can provide!