Rotary axis jumbled

Looks to me like the rotary is just slipping.
A few contributing factors:
1. Looks like this is being done in line mode. That will require your rotary to turn back and forth which will be hard to do without slip
2. Seems like the cylinder is not retaining position along the long axis when rotating back and forth
3. Your speed/acceleration settings may be too high for your equipment with this operation
I’d suggest moving to a horizontal scanning/fill operation making sure that the rotary only ever moves in one direction.