WotC Booster Pack Help

I just recently purchased a collection of WotC booster packs off eBay. The seller seems VERY LEGIT; he actually has a bunch of WotC Boxes that he’s slowly opening and selling off - his eBay Listings state that he will not sell “heavy”/“light” packs for more/sell.

Anyway, I bought a bunch of loose booster packs for my collection. Most of the booster packs appear perfect; however, all three Fossil Packs are a little different… Specifically, the silver-strip running along the back-side of these booster packs. Along the “corrugated” portion, there are a few small lines running diagonally up-and-down. I am 99.999% sure these are not re-sealed at all; however, I’m not sure what’s going on with the diagonal lines along the “corrugated” portion.

Is this common for booster packs - is it just a slight packaging defect?

Any help would be much appreciated. THANKS!

EDIT: I’ve uploaded a picture of one of the Fossil Packs. I also found a 1st Ed. Team Rocket Pack with the same issue. Any help would be much appreciated - THANKS!

If you have a few then maybe chance opening one of them to find out? It’s a small cost to pay to verify if the packs are likely to all be legit and not resealed.

Photos to better demonstrate what you are speaking of?

Figured I’d probably need some pictures - just uploaded a few.