It looks like your middle assembly is loose, somehow. The uneven milled surface on the bottom of that coaster seems to back that up and the gcode is circular. A milled surface should be pretty amazing. Being able to see such distinct lines says either you are using too high of a step over, your tool is not perpendicular to the work surface, or something is loose.
Extend your spindle down to about an inch from your spoil board. Put your finger on the end of the bit and wiggle it. If it wiggle noticeably you are lacking proper rigidity. It looks like you are only loose on one axis somehow but the video is so zoomed in I can’t tell what axis exactly but it will be the one that is perpendicular to the flat spot.