I also posted this reply in theoriginal Tradgang thread:
I think I resolved the problem. But I’m still failing to understand it.
I lowered the nock height back down to 4/16 (lower edge of the nock) and now the bare shaft flies pretty good. I find 4/16 rather low but this solved the problem in this case.
But I just don’t understand why these arrows behave this way. If I go up with nock height just a little bit the bare shafts start to fly with nock low.
Does someone have an idea?
Michael