Your raised floor sounds normal to me. Mine lifts, moves inward, then the outside top seals and the inside bottom lifts as the slide continues inward to seal at the bottom. Does the slide seal all the way around in both positions? First rule of troubleshooting " If it ain't broke, don't fix it".
As for you measurements with the slide extended I would ask: Is the ground level compared to the trailer? I would check the ground, trailer frame and the slide out level in respect to each other. If in fact the room is off kilter, I would be checking for the cause. You could have a roller problem in the tubes.
I can see no indication that the unit has slipped from your pics. I would check for marks at the end of each arm to see if anything has moved.
If your determined to adjust it the nut on the far right side of the bottom pic would need to be loosened. Then loosen the jam nut on the long bolt extending downward beneath it. Use this long bolt to raise or lower the room. I would use a jack to relieve the pressure on the bolt's threads. Move the bolt the amount of difference and tighten it all back up and recheck your measurements.
2012 Chevy 3500HD Dually 4X4
Crew Cab long bed 6.0 gasser 4.10
2019 Open Range OF337RLS
Yamaha EF3000iSE
retired gadgetman