Did some troubleshooting on my own:
With DPI at 317.5, Reduced Speed from 6000 to 4500mm/m
-no effect
With Speed at 6000mm/m Reduced DPI from 317.5 to 211.7 (Line Interval 80µ to 120µ)
-no effect
Reduced BOTH Speed and DPI to 4500mm/m and 211.7 (Line Interval 120µ)
-successful print (tested multiple).