Well...
Looks like stove is still "a work in progress."
Spent the morning on the phone with Tech Support at US Stove. After trying several different things, they believe the controller board may be faulty on my stove. They are sending one (overnight I think) to swap ou the bad one.
Quick note: If you want to adjust the threshold for the Draft Fan on a 5500M, just hold down the draft fan up and the aux up simultaneously..this will change the higher threshold. Press on when you have it set to what you want. Repeat for the lower threshold by holding down Draft Fan down and Aux down.
We'll see!