R2880 leaves hair line scratches. Cause ?

[Aristoc]

I looked at two new prints and noticed 7-8 full length hairline scratches on the print from the R2880. They are straight and parallel. They are full length even though I can only show a partial on the photos below. here is the best  pic of what i mean. This is new Epson Exhibition fibre paper.

Do you know what is the cause?  Thank you .