I don’t know if it’s the release. All I know is that usually a fixed crawl requires some minor adjustment of tuning, which could honestly be ignored without much ill effect. So because your experience is out of the norm, we look elsewhere for answers. The irregular arrow flight is more concerning than the noise. 3 under is a noisy way to shoot, at least compared with split, and adding a fixed crawl is noisier than a regular string grip. But it should be a small increase in noise, not wow! that’s a lot noisier increase in noise. A poor release can cause more noise than expected, and also poor arrow flight.
After many years of mostly mediocre shooting, but trying really hard, I can still go out on the range and start plucking without even knowing it. The only way I know it is that my arrows are impacting right, and I know I’m not creeping. I creep too, occasionally, but I don’t have to look at the target to know when I creep. I’m not talking major, wave your hand at the crowd plucking where the arrow ends up off the target. I’m talking a slight delay in relaxing my fingers so my fingertips catch a little bit of the string, just enough to throw the arrow off course so it lands 6” or so to the right. I can’t force my fingers to relax any faster, but I do know what it feels like when they relax when they should, and how to achieve that by focusing more on my back tension.
The whole point of this was not to give you a lesson in not plucking, but was to illustrate that even though I should know better, I can still slip into plucking even when I’m doing everything the same way I always do. So yes, if you change things, like adding a fixed crawl, it can give you a few things to work on that you might not expect.