Welcome to the forum! I think I'd crawl around and do a thorough visual inspection of the lift cable system for broken, worn or binding components. Popups have been known to bounce around in ditches and stuff and there could be some damage especially on the rear corners...you mentioned the right rear corner which is on the ditch side.
Next I'd do as Seann says and make sure everything is lubed up good. Use some spray lube on the telescoping lift arms and good old grease on the cables.
2006 23B Hybrid with 10k round bar WDH
2011 F150 4x4 SCREW Ecoboost, Max Tow, Integrated TBC, 3.73 LS axle, Firestone Ride Rite airbags.