Anybody using the Undercover bed cover? At the very back of the truck bed the edge of the cover is scratching my paint. Anybody else having this problem?

Anything you put on your truck that doesn't have some type of protection between it an the paint has the potential to do this. By anything, I'm including mud guards, tonneau covers, bed rails, camper shells and anything else you can think of. Movement is the cause, either the added item moves against the paint, the body flexes under the mounted item, or both. The paint on these trucks is very very thin, and it doesn't take long. In the case of bed mounted items, one answer is line-x or rhino lining. In some cases if the movement is not major, 3M clear tape can be sufficient.

i have the undercover bed cover and dont have any problems with it at all

i have the undercover bed cover and dont have any problems with it at all

Same here, but my truck bed has Line-X over the rails.

installed incorrectly. loosen the rear most clamps and slide it away from the tailgate so theres a 1/8th to 1/4 inch of gap, you may have to re-adjust the latches afterwards. the cover should not touch the paint open or closed.

Same here, but my truck bed has Line-X over the rails.
X2