Shape Pen Tool Error

I do pretty heavy graphics work in Keynote and for the last 2-3 years I've seen a major problem with the Pen Tool used to create shapes. Given a shape with multiple points, if I start to drag a point one direction, I'll see all the other points jitter and shift in a direction even though I'm not interacting with them. The jitter and shifting seems to increase with the number of points in a shape. It's become a big problem because even a minor adjustment of one point makes my entire shape shift out of line. The longer I hold on to a point (even without moving it), the more extreme the other points shake. I'm happy to include a video if that would help.

Has anyone else noticed this? Or are there any suggestions for how to mitigate? I've tested if it's better or worse with more/less points, if I unselect the shape after each movement, saving the Keynote more often, etc. TIA.

Here's an example of the graphics I do and how many points I'm usually working with: