If you use it in off hand than it's not a bug.
It should not add the wisdom modifyer to the damage in off hand.
Out of that i never saw this bug in a not modded game and I played sooooooo much.
So if you do a ranger Dual Wielder with 4th level Druid Initiate and grab Shillelagh can you then have it in off-hand and have the wisdom bonus?
