I’m having a similar issue. I’ve tried un-taping and re-tapting the rails, everything is even, the impression is good and consisten, the rollers are brand new (no flat spots) and I’ve conditioned them recently. there’s just a blank spot that moves around the image.
Below is an image of several scraps where the blank spot appears, then affects different areas, then is gone and everything prints fine for several runs, then it reappears again …
Help?