Fort Maceo

Greetings all. Has anyone installed the BAK Revolver X4S tonneau cover on their GMT800 recently? It's the same part number (80101) that fits 1988 CKs all the way through 2013 GMT900s, so if you installed one on something before or after a GMT800, you can probably answer my question, too. I think they changed the design of their rail seals recently so if you installed one a few years ago, this might not apply. See my two attached pictures. The rail seals on my cover that I tried to install today stand up about 3/8". The ones in every single picture I could find online shows flat seals, so they possibly changed it recently. Standing up like it is in my pictures, there's an almost 3/8" gap above the tailgate when it's closed. The instructions state to push the rails down until the rail is about flush with the bed rail. If the rails were down flush, the tailgate gap wouldn't exist. It makes sense that getting the rails down to the bed rails would fix this problem - not to mention just looking better flush than sticking up above the bed rails. This tall seal is fairly stiff. I can probably pull it down with bar clamps, then tighten the supplied clamps to hold it down; but want to make sure I'm not missing anything before I tear up brand new (and expensive) rails. And, of course, today is Saturday and their support is closed. I'll sleep on it and try it again tomorrow. If I can't sort it out by Monday morning, I'll call their support then. Thank you for any guidance you can provide in the meantime.