If your tool isn't center cutting #1 will cause a lot of problems, and so will #2 and #3. #2 will be problematic if the ramp is too steep. #3 will be problematic if the sprial diameter is too small (At least .7 more than the diameter of the tool) so that the tool is forcing the center down in an area that isn't cleared OR the spiral ramp angle is too steep.
If your gibs aren't adjusted properly AND/OR your lead screws have too much lash, you will get terrible cuts anytime the mill starts to take an earnest cut. Poor gib adjustment and/or lead screw lash in any is will cause problems