Not a major problem but annoying nonetheless.
I’ve duplicated a logo for a friend’s biz in Blender.
The curved background is fine in preview render but when I do the actual render (F12) the curved plane in the background has noticeable banding where the plane curves up.
I’ve attached a couple of photos showing the issue.
Render on left, Preview on right. Both approx same number of frames…about 60
FYI - AA is set to “Full Sample” if that matters.