When I look at the daily differential report for 2/5, I see that the exercise calories are 604. When I look at 2/6, the exercise calories are 363, which is consistent with what you tracked for that day. Is it possible you were looking at 2/6, thinking it was the data for 2/5?
"You may have a fresh start any moment you choose, for this thing that we call "failure" is not the falling down but the staying down." Mary Pickford