Hey there emudevs!
I just have a quick question as to why this is occurring on players that don't have any items even equipped in this slot. It shows up either checkered, or even a weird shirt that seems to disappear. Here are some screenshots.
I have removed all patches from my wow folder and they still show up as well. And with the patches they are still there. I don't have anything defined to be in my hands as a visual when you don't have weapons, or a shirt when your don't have a short equipped. Any help would be much appreciated.