For lack of any better guideline, I leave the Lightroom print resolution set at 360PPI when sending images to my R2880. Sometimes I get some banding, like a pattern of 1/8" checks, in light, relatively featureless areas of prints--both matte and glossy.
Thinking it might be some sort of moire that would still be there at 720, I just tried one of the problem prints at an intermediate value of 600, and it printed out very nicely. I can't see a bit of difference in fine details (hairs on closeup of butterfly), but it made a huge difference in the background, smoothing out the objectionable banding in the areas that have no detail.