Snap and coincident not accurate

Hi Guys,

I got the error that there are gaps.

But when using coincident when sketching two lines to connect two circles, I see that the point are not joining.

When i just sketch 2 lines between a circles edge, using the auto snap, this line is also off.. (when zooming very close)

How dous this come ?

Thx !!

SolidworksSketching