You’re missing the point, 1000%.
Doesn’t matter what either mfg says.
And “level” by definition, when the camper is sitting on the truck and truck on any surface, even if you “think” that surface is level (which you’d never know without verifying) still has nothing to do with either the optical illusion or the physical measurements of the components in question. (Which you haven’t done, reference my last post for what to measure)
Until you do that you can surmise all you want about why it looks like it does, and you’ll never figure it out.
I do realize being able to conceptualize what I’m saying might be difficult for you.
But I promise 100% I’m not trying to mislead you and if you take 4 simple measurements, you’ll figure out exactly what is going on.
Put away your bubble level until you’re actually leveling it up at a campsite. It is not part of the equation here.