1. There is a gap (X axis or Y axis) in the machine tool screw
2. The tool tip angle is not considered
3. There is a gap in the slide plate and the wedge is loose.
4. There is something wrong with programming (arc setting is incorrect)
5. The machine tool system is aging, and it is not recognized or the interpolation is not obvious
6. The knife tower is not fixed after positioning (the incidence is extremely low)
And, oh, forget it! You'd better find someone who knows.