Drawing a simple line, artifact on screen (probably me doing something wrong...)

Ahhh, thanks a lot Pete :blush:
I could have told myslef that, the line looked too “human made” to be some artifact, why on earth I did not think about that I don’t know :face_with_raised_eyebrow:
Thanks a lot for helping a noob with this, much appreciated!
Regards,
Carsten