Your Side seals are pulling out from under the Vertical cover I have circled in red on the attached picture.
From my research (I have a 2020 Vista 27P with same slides etc.) the side seals are either a "Co-extrusion" where the soft "P" shaped seal & wiper flat seal are extruded on a hard plastic flat and that plastic flat part is pushed under the side vertical covers. OR the P seal & wiper flat seal are just glued to the hard plastic flat (I can't tell on mine for sure how the seals are made.
On my 27P vista I had to push as best I could the plastic flat back under the vertical trim cover and then used 3M automotive window trim adhesive to glue back in place. While on my vista not totally back in place, I could still see the hard plastic flat part starting to get in contact with the Aluminum teeth on the gear rack (mainly the Top ones). I could hear a click, click, click sound as the slide came in/out as the plastic was in contact of the teeth. I used a utility knife to trim a small notch in the plastic where it was in contact of the teeth (stopped the click sounds).
Also I used the same 3m Trim adhesive to glue the bottom side of the seal back in place of the flat plastic part where it was loose (Used tape to hold in place for 24 hours). While not factory perfect it is working to keep the seals from engaging the gear teeth on the Aluminum Rack. Really Important issue is to keep the rain water out of the top side areas that our Motors are located to prevent a failure.
Your King Bed slide like mine rest on top of a deck with drawers underneath and there are 2 metal plates the rollers (Or teflon/plastic) slide plates slide on top of the plates make sure the plates are smooth and show no gouging from foreign mater caught between the slide & the deck.
Suggestion from me, First clear the areas around the seals that come in contact with the racks both Outside and Inside (you have 2 seals one inside & one outside). Once certain no interference, Then with slide retracted do a "Re-sync" of the motors (Lippert has Youtube videos on how to do it). This will correct issues with slide not going out even on both sides.
Couple of observations from your pictures: 1) the top rack on the attached picture in my reply it looks like your rack is "Bowed" quite a lot. This could be a sync issue but if not addressed the stress on the rack will eventually either break the aluminum rack or the plastic mounting blocks of the Rack to the Side walls (Or the 4 screws that that attach the blocks to the Side walls.
2) your seals are letting a lot of "Stuff" bypass and getting behind the seals and perhaps the motor and/or worm gear that drives the racks. If the Motors fail when in the out position, I don't see enough clearance between the slide & the back wall to get a ratchet in place to manually retract the slideout.
I have NOT contacted Lippert about the correct side seals for replacement but in the near future will as I know my time is drawing close to replace. Lippert website only shows 2 different side seals for the slim rack and neither look correct. Generic ones "Might" work (like from Steel Rubber Products but are not the same).
