I have this annoying AE problem which I can not fix!!!. it always happens with very large comps. when I key the position of a large comp (or a large footage) inside smaller comp, after effects sometimes add an unwanted spike or overshoot into the animation which is not even constant. it seems so random. I was struggling with the issue and one of my coworkers mentioned they have the same issue with large files and comps. if you look at graph editor you can see AE added the spike to the motion. the easing and editing seem not helpful either.
the large comp is 110x10600 (1.00) 30F/S and the small one is 1820x1024