Force Move tracking issue

I am a few days in to programming bench testing my first FORCE program, and having an issue with consistency

The waypoints are taught to follow the edit of a part, and I want to use the FORCE mode to apply pressure inward
basically, exactly like this example

However what I am seeing is inconsistently applied force / positions. Attached video has 3 back to back runs; run 1 works well, run 2 drifts off the part after the turn, run 3 is sped up and drifts WAY off part.

I locate the part edge with a direction move until contact, then use MOVEP inside the Force setup.
I am using Point force with a point position taught in the center of the part. Y direction of 5N \ 500mm/s

I know my movements are rough, but i want to figure out / understand this issue before i move on to better teaching