Its bouncing of a object that's not at a exact 90 degree angle, Or the bounding box of the object is not straight.
You can try fix the angle, or collision box.
Or you can add two waypoints, On on the left, one on the right.
System on start of layout:
If you cannot figure it out with bouncing, then that solution should be a quick fix.
If its for your spinny saws kinda things. I recommend the sine behavior.
- It looks allot nicer, as it smooths the stop and accelerates to the next position.
- its controllable, Speed, distance to make the wave ect.