Use the link and group shoot bare shaft tune.
If your form is good and your bow is ok you should be able to shoot a good bare shaft. You may get some variation due to form, but you should see a pattern. That is a good bow and cut to center so it should shoot a wide range of shaft spine. I had one and it shot great bare shafts when tuned and with good form.
How far out are you shooting? Don't get to far out if your form is not real good. Get close and work back. From close up you may see something more clearly. If you can't hit the target every time at say 10 yd. and start to see a patter then something is really wrong.
Here is one possible scenario that could result in what you are experiencing. Say your nock set is too low and your arrow is too stiff. You are very close to getting hits on the riser, shelf, and edge of shelf. Now throw in some less than perfect form. One time you hit the shelf, the next the riser, then both kind of, or the edge of the shelf and then maybe you get off a good one with no contact. The bare shaft can kind of go straight, then a riser hit and it goes false weak or about right. Next shot no riser so it looks stiff, but you hit the shelf and the bare shaft goes low……….. Bare shafts that are way too stiff can go right and left depending on form. Too low a nock can go more straight or low if it hits the shelf. If they go way high and low you have a problem with form and or the bow, because it is really hard to go under and over a target with a bare shaft from tune issues.
Here is what I would try. Screw on a lot more point weight to make sure you have a weak shaft. Raise the nock point so you are for sure too high. Get that bare shaft shooting weak and low very obviously. With that set-up you just can’t get fulse readings from bow contact with anything close to good form. Start to work down on the nock location until you level out reasonably, but still a little low. Then start to back off on the point weight until it in close to the fletched shafts. Now you can watch form and fine tune.
Also make sure you shoot the same exact shaft type, length, and point weight with the bare and fletched shafts. If you mix you will have way too many variables. Don’t change until you have a very well established pattern. I like to be able to repeat a pattern of bare shaft flight over a lot of arrows and several days before I make a big change.