Neat they added that. It may be just a little off. Mine was off by a digit and was a PIA to change. However if it did it before you had it and this is the new one. I would guess it’s getting air in somewhere. Test the exhaust easy, no mess with windex. It’ll blow bubbles if it’s leaking at a flange. Used to add a second snap ring to older ones to get tighter but neither of yours are old.
Next step is messy but works by vacuum lines is wd-40, idle will change noticeably and won’t blow up in your face like “ether” lol.
Or the FUCK IT! method, it’s going to dealer also works.