From your description of your problem, you may have to look past bare shaft tuning to find your solution. It appears that something may be interfering with the expected flight characteristics of your bare shaft or fletched arrow. I think we can rule out false weak, as I would have guessed a .400 spine based on your setup. There may be quill interference on either your fletched arrows or your bare shaft (if you leave quills on your bare shaft, as I do). I have solved similar problems in the past by adjusting brace height, varying finger pressure on the string, the string itself, silencer location, type of string grip, strike plate and shelf rest material and position, arrow nock fit, and brand or diameter of the arrow. You have another wildcard: your fixed crawl. You might want to see if the bow will tune first without the fixed crawl, as that was how it was designed. Lots of possibilities when a bow won't react as expected to the usual bare shaft tuning changes of point weight, arrow length, etc.