Can you upload a more highres image with a ruler in it?
What process of dig-negs are you doing?
What resolution in QTR? (it should be 2880, uni-directional).
What type of black ink are you using?
What curve, etc?
Platen gap? Media thickness settings? Paper feed speed setting?
I can’t say our CCPro ink is optimized for dig-negs as we have spent a lot of time optimizing and building PiezoDN with Piezography inks. That said, it should not be making marks like this at all and several people claim the CCpro ink is better for dig-negs because it blocks more UV.
Please let us know the details of your printing environment and we can see if there is an obvious reason for the marks.