This is likely caused by some kind of stretch scaling artifact as bucko says. Generally something that stretches the vertical disproportionately to the horizontal.
I’m not familiar with other dvdo products, but on my dvdo duo I can change picture aspect ratio, active aspect ratio, and zoom +/-, without distorting the scanlines. However, actually changing the vertical stretch independently will result in similar patterns to what you show.
Then again, I recently tried a lumagen HDQ and no matter what settings i changed (after messing with it for hours) I couldn’t get it to not have those distorted scanlines. So YMMV.