Why is there rubbing at front of slides?

[Vmaxkid]

I have a 2018 Sidewinder LTXSE and I just had the shop install Dupont slides. They literally have only the miles to be brought in and out of the trailer since installed. I’ve never seen this at the front rails. they also installed Barn of Parts cross shaft saver and center shock cross shaft. Any ideas? No issues at rear where you might normally see it when the track is not aligned properly. It’s on both sides. Or is this just how these are finished from the factory at the front of these slides?

 

[KnappAttack]

They are ground that way to match up with the rail protector from the factory because they are a bit wider wider than stock ones.

 

[Vmaxkid]

Great thanks.

 

[no1b4me]

Also tapered to fit through the lug window easier during install if the skid wasn't removed.