Why is there a 1mm difference between the CAD material and the drawn graphics? After overlapping the drawings I drew with the material graphics, I found that there is a deviation. The difference is 1m

Why is there a 1mm difference between the CAD material and the drawn graphics? After overlapping the drawings I drew with the material graphics, I found that there is a deviation. The difference is 1mm. Could you please help me?

Some time ago, I downloaded a material from the Internet, and there were deviations when I drew it according to the size. Later I found out that it was because of a problem with the linear annotation. The accuracy of the labeling on the material was 0, which means it was only accurate to Single digits, all numbers after the decimal point are rounded off. Try changing the main unit linear dimension precision in the dimension style and then check the material size