I wanted to have a video to better show what I mean, but couldn't get OBS to work with RA2 on short notice, so I only have these screenshots.

The rotor spinning animation is 3 frames long, one of the frames it seems ok but the other two are further out. I've checked the HVA file and it seems fine https://streamable.com/2ubibe.
It was a few months ago I added this but only just gotten to it at the bottom of my list of stuff to do so it's hard to remember what I've already tried. I know I tried deleting and remaking the HVA but this was still the result.
The helicopter I'm using is the one from here https://ppmforums.com/viewtopic.php?t=30971
I have a couple of other helicopters with a similar problem but this one's the worst for it. What can I do to fix this?
I also attached it so you can check it for yourself if you wanted to.