Any chance the blade is slipping in the blade clamps after tensioning? Looking at the circle you cut, it looks like there is not enough tension on the blade to stay on the line with the thickness of wood you are cutting. Try this….tension the blade, cut a circle, then release the tension. Push down on the top arm. If there is a large bow in the blade, it means the blade slipped in the blade clamps. If not, I don’t know what the problem is.