I equipped my wand (from the item menu, not just taking it off my back) after drinking a potion of giant size I received from a quest in the starting area, and noticed that my wand was still normal size despite me being giant. After the potion effect ended, I shrunk back down to normal size, but my wand shrunk down with me. I was running around with this tiny tiny little wand as a regular person, it was quite hilarious.
I took some screenshots: https://imgur.com/a/h9mJB
The effect persisted even after putting the wand away and taking it back out. The only way to fix it was to un-equip the wand and re-equip it from the item menu.