Cezanne scan lines

[Clickwrr]

Hello, hoping the collective knowledge of this forum can help. I am getting regular scan lines on recent scans, but only in the dark areas, not in lighter areas and not on all scans. Possibly insufficient warm-up time? Pic attached. pic is 200% view in PS, scanned at 4000 dpi.
Info: 5500, G5 with max ram, scan bed great condition.

[Corran]

Have you cleaned off the mirror recently inside the scanner?

[Clickwrr]

Yes. Mirrors/Lens cleaned recently. The lines are only on the dark areas, and when they get to the lighter areas, the lines stop; which might suggest it is not dust lines, as they should continue on into the lighter areas, I would think. but thanks for the suggestion.

[Corran]

Strange. When I've had lines they've been across the entire scan regardless of density, but sometimes they are not noticeable unless you brighten/darken parts of the image. Even with cleaning some lines can persist. Very few scanners seem to not have lines at some point in certain situations unfortunately.