The bottom of the Reckless bags takes a ton of abuse, vibrating against metal, and eventually, the wear spots will work their way through. This is not a big deal - it's part of the typical wear pattern on this system, and it's why we ended up adding the foam on the updated versions to help reduce chafing between the harness and the bike.
Here's a video that gives a deeper look into normal wear & tears on the underside of a Reckless system. Please note that the video reflects a V2 R80 without a foam backing.
If you need to replace the foam, purchase it directly from our U.S. shop or EU shop.