Horizontal line(s) appearing, easily removed by slightly adjusting strength

In many images processed in my case I see a horizontal line in the preview, usually in 1/3 from the top of the image. Alternatively sometime weird artifacts show. Afaik there is no specifics an images should have to cause this behavior, and it is in approx 20% of my scanned negative images.

To reproduce: Select a couple of images from macOS Photos, right-click “Edit in Topaz Photo AI”, which launches Photo AI extension with all photos in there. The autopilot will determine for each image the initial settings, and approx 20% of the images I then click and let the preview generate will have this horizontal line(s). I mostly use noise reduction.

The good thing: To remove the horizontal line, the only thing I need to do is move the slider of the noise reduction strength and the line(s) disappear. I’ve seen it happen in all two models: normal, strong.
This workaround works 100% of the time, making this more a hallucination of the model than maybe a bug maybe.

Topaz Photo AI [v2.1.2] on [Mac]