Storage box

[jeffp_032056]

Picked up a crossover tool box for my new 2017 1500. Went to install, placed it on top of the plastic that covers the bed rails and saw that the plastic bed rail covers aren't flat. They are higher on the inside of the box and lower on the outside, about a 1/4" difference. So what this means is that when I installed the box it did not sit flat on the bed rail cover, it only made contact on the inside edges. Thought I'd try it so I installed and within a day it had lifted / warped the outside of the plastic bed rail cover on both sides. Of course I immediately pulled it out but "what the heck"? I've had numerous trucks since 1996 (not Dodge) and I've put boxes in all of them with no problems.

Does anyone have and idea what's going on, is this normal, etc?

Thanks in advance for any help or suggestions.