Smudge on inside of PSA slab?

So I just received this slab in the mail about a week ago and I’ve just realized that there seems to be something like a smudge on the inside of the slab. This is a bit disappointing considering the cost of the card/slab. The smudge wasn’t visible in the pictures within the listing, which makes sense considering you can only really see it under certain lighting. I’m hoping to get a second opinion on if this is just a smudge on the inside of the PSA slab case (plastic defect) and not damage on the card itself? Has anyone else ran into this issue before with PSA slabs? I’m almost positive the smudge is not on the card itself, but a second opinion would definitely give me peace of mind. Thank you :)