Canon imagePROGRAF Pro-4000 Streaking Issue

[Artable]

I have several Canon pro series printers and have experienced the same issue on 3 of these printers. Dark prints have streaks running throughout the image, but the nozzle test prints a perfect nozzle every time. 

The head is fairly new on one, less than 1,000 prints. 

Has anyone experienced a similar issue and can you guide me in the right direction to reolve it? 

Any help is greatly appreciated. 

[zachthomasphoto]

I'm having this same issue on a Canon Image Pro 4000. Did you find a fix? I thought it was from the paper but even after changing to another paper roll, I still have the patterns. It's definitely noticeable in the shadows.