Compression totally wrecked my last upload too, just flattened all the shadow work. @waderamirez is onto something with the color profile thing, it’s such a hidden trap. I fought with muddy colors for weeks before someone told me my editor was set to ProPhoto. Saved as sRGB like they said and it was a night and day difference on the site. The combo of bad compression and a missing profile will destroy your art every time. You gotta check both the export size and that color space.