Hi Matadem, there isn't any method in PDF files to have exact circles. It only has either lines or general Bezier curves.

So something that looks like a circle in a PDF is not precisely an actual circle, it's just a generic spline curve that is shaped similar to a circle.

The one in your case here deviates from an exact circle by around 0.003 units. It's a little too much deviation for MoI to consider it a circle.

- Michael