Thanks for replies everyone!
If there was some fault in my Ultra Rest HD, then maybe. Didn't test this with powder or anything, but since I could get the bow back in tune with arrow rest adjustment, so I don't think this is the case.Also could you be getting any rest or facial contact?
No. Paper and broadhead tuning. I use paper test to bring tuning close, then finalize it with broadhead tuning.Also have you tried a bare shaft?
So basically there is no big problem - the arrows fly great now, I just wonder what caused the need to adjust the arrow rest more to the right. One thing though: I use No-peep, and since I also had to adjust my sight pins more to the right, the No-peep blocks the sight picture more than before - it also almost blocks the bubble level of the sight. That's one reason why I preferred my initial tuning. Although this could be fixed by moving the No-peep to an upper position on its mounting bracket.