I have had this problem in the past, I would suggest that you carefully cut the feathers off of your three fletched arrow, making sure to leave the quills.
Then I would suggest that you place one of the quills at the twelve o'clock position. This will have one of the hens just at the outside edge of the shelf, and the other hen at the crease of the shelf and the sight window.
I like to use velcro pyle, but use whatever shelf materail you wish, but leave a little opening between the side of the sight window and the shelf near the crease. This is for your hen, close to the sight window to slide through. This will likely require you to turn your nocks so that the travel of the feathers can follow the path I have just described.
Shoot that quilled bare shaft for tune. When it is flying with no contact to the shelf material, or with the least amount of it, you will be set.
It is the quills that are giving you fits....