Welcome to FRF
I'm not sure how the slide is made on the 2318G, but the possibilities could be:
Slide mechanism not installed properly,
Slide out of adjustment,
Slide mounting hardware loose on missing.
Have you tried contacting FR yourself?
I had poor dealer support with my TT and I called FR(Rockwood Division) myself. They were very helpful. The information below might help you.
Tent Camper Warranties
(574) 642-2640 Ext. 105
Fax (574) 642-4999