in yellow you have two nulls? parented to A and B right?
You’re linking the puppet pin via expressions and pick whipping each null’s position?
If you’re just doing that…you’ll end up with a wrong value (since the null is parented and it’s position value is the offset of it’s parent and not it’s screen position)
to link them properly you’ll need to paste:
a=thisComp.layer(“Null 1”);
a.toComp(a.anchorPoint)
instead of pickwhipping.