drawArc on fenix3 produced vertical lines

Hi all together

I use many drawArc functions in my watchface. All are drawing correct on all watches and on Simulator but not on some fenix3
Two users send me a reply with a picture that show vertical and horizontal lines at the end of arc.
Here is the drawArc command that produced a vertical line:

dc.setColor(Gfx.COLOR_WHITE, Gfx.COLOR_TRANSPARENT);
dc.setPenWidth(1);
dc.drawArc(109, 443, 300, Gfx.ARC_COUNTER_CLOCKWISE, 74, 106);




The latest Firmware is installed on fenix3
My current SDK is 2.4.9

Is this a know issue?

Best regards
FSeifert