Resetting custom tool names only works after changing the name.

What's the bug
Resetting a custom tool's name via replacing it with a space does not work til you rename the tool to something else, then change the name to a space. Attempting to change the name without renaming first just causes the item to flash briefly in the output slot.
How to reproduce
Attempt to reset the name of a previously renamed custom tool. Where did the bug occur All realms
Additional info
So far I've only encountered this happening to custom tools, seems fine with custom armour and both vanilla and custom blocks. Have not tested everything though, so may be more.