You're not missing anything. 3200 lbs on the front axle is around 1/2 of what 2 load range e little tires like you have are rated for. Hence the 40 psi MINIMUM pressure for 16xx lbs per tire. (Rvnet number crunchers, I did not look this up, so don't not pick the fine print. I'm talking rough numbers)
As said, the door sticker is a "safe" all around pressure.
Nothing to worry about, however, I'd run 10 psi above the minimum calculated pressure to help with cornering/handling.
Don't worry though, the peanut gallery will try to help confuse the issue.
My casual observation is (assuming this is a class C camper) that the front end seems pretty light. Is there a bunch of weight aft, taking some weight off the front axle?