Animate Pro 3: Deformation changes every frame

Might be a very basic and simple problem but I’m stuck in holding pattern here
Have set up my characters with deformation rig, creating keyframes, can move the parts, but when I go to deform them, it deforms every frame back to the start
I want to just deform on selected keyframes, animate and then move on, this is basic stuff, why won’t it work for me
Any help appreciated