Late on this one.
Looks like your ODK big slide based on the photo. I personally don't think it's the gasket as that just looks folded over and rubbing. My unit has black steaks all over it from them that I have to clean off a few times a year. The more telling marks are flooring marks which you should not see.
The controls are in the pantry under the lowest shelf. You must hold the button down for the 3 seconds after each cycle to set the end points or you will have an issue with the BH slides due to their size, especially the ODK slide with is extra long. I don't let anyone touch the buttons except me. Also don't forget to close the BH door before you close the main slide.
Dealer ripped my door off during warranty work once.
Lippert has improved the motor wire mount on these since 2014, but you will most likely eventually have a motor fail at some point. My suggestion is to carry a spare if your handy as you have 8 motors in this unit.
Last trip I have a wire come loose from a solder point due to road movement (2nd one back there) and I had to repair at the CG. Override got it out for me, so at least that worked. The last one was repaired under warranty.
Hope the dealer gets you going quickly again.