HiYes, it is very weird. The chain could have been an explanation. But even a very large black wallet would not be able to stain the side corners that strongly. It's a mystery.
Do you think it’s worth taking in to LV store ( the closest to me is far away) , and would they clean in for free?
I think the staining is from the bag itself, as the crease and stained line is exactly in the spot in closes