CAnimKnob Arc doesn't show starting position on Windows

Hi!
I created an object that inherits from CAnimKnob (VSTGUI4) and draws a blue arch around to show the value of the parameter (using path->addArc()). In the 0 position of the knob, a blue dot should show up. This only happens on macOS, but not on Windows. (However, when I turn the knob around, the blue Arc fills up on both Mac & win). Is there something I am doing wrong or is it a bug?

Thanks!

macKnob
windowsKnob
turnedKnob