I have no idea where to post that bug, but as i have it at least each time i use the mouse scrolling in my inventory, i post it here anyway.
At first thought it was from FurniturePreview but nope, no .lua of those are in the folder.
I can reproduce it each time i scroll over any item in my inventory be food, armor, weapon.
The addons i use for inventory management is : IIFA - and on some characters but not all is AutoCategory.
But i can not say if it is only ESO UI or addon concerned as this happens either with addons or NO addons at all.