Shoot a bare shaft , and see what that does.
I'm about to try some bare shaft testing myself. I've had some odd problems with kick off that has been very irregular. Sometimes every arrow kicks off to the left then after shooting 6 or more arrows the next dozen or so fly straight as a string.
My groupings have improved as my form improves though I still have fliers.
I'm using some very sturdy low priced arrows with supposedly a 500 spine. I suspect they are much stiffer than that. They have withstood multiple impacts with the timbers of my backstop, the heads buried deeply, without cracking, which other arrows I've tried proved to be much too fragile to withstand even once. None of this batch have cracked or been damaged till today.
Today I got a very tight grouping of three arrows but managed to badly damage one vane nearly ripping it in half . I fired that damaged arrow off several times and was surprised to find it still flew straight and near dead center every time.
Since other than the vane that arrow is undamaged I figure its a candidate for stripping the vanes off completely for bare shaft testing.
First I'll try trimming all three vanes to a very low height, as Ishi is said to have trimmed the feathers of some of his arrows. Not sure if this will have any beneficial effect. Worth trying and nothing is lost.
The rubbery vanes of these arrows look to be much thicker than those of other arrows I have. I suspect the vanes may be adding too much weight to the rear end and thats why they cant unexpectedly. Any slight variation in my draw and release seems to be greatly magnified.
So long as I stay in the zone and make sure my draw is full lenght and release are consistent I get good straight flights with decent groupings.
PS
I've improved greatly in the last few months since the Covid vaccine reaction nearly wrecked my shoulder muscles.