Minecraft: 1.19.2
Fabric: 0.14.21
Mod Version: 2.6.8-release

If I swap a wand with the item in my offhand while also opening the wand menu, then I can occasionally get the menu to open without the wand in my main hand. If I then make any changes to the wand menu, it then saves to the other item instead:

Additionally, if done to a second wand, then any tools stored in the first wand get duplicated: