Yes it’s a huge gouge on the backside. Each of the four had the same gouge on the back and it was deep enough it was noticeable on the front.
these zeros are fragile af ... i really even scared to put them on my face - a lot of lenses will have cracks on bridge sooner or later.
imo another bigger problem will be peeling of the outer lens, where the mat is cut, the edge is clearly sharp and may peel when cleaning
ps. i have carbon and planetx perfect 10/10