Export options grainy – Desygner: Design Any Graphic Review

So, I love be the app but am struggling to export the files hi-res...actually, not even hi-res, just how they appear on screen before export. All of my exported projects look grainy - unusable even in website banners. I’ve reached out via feedback on the app but no response.
Review by zyxwvuts on Desygner: Design Any Graphic.