Frank Goossens on "[Plugin: Autoptimize] Header Settings Overriden With Plugin"

Evening WolfSpiritDesign;
Well, there'll probably be a tiny bit of inline CSS which is now moved to the autoptimized CSS-file. Due to that CSS not being inline any more, it's considered just as important as the rest of the CSS (whereas without optimization it's considered more important).

You could either look at the HTML source of the page without autoptimized CSS and try to identify what CSS you should exclude from being aggregated, or you could simply stop AO from aggregating inline CSS by adding this to a seperate plugin or your (child) theme's functions.php (warning; theme updates would override your changes);

add_filter('autoptimize_css_include_inline','WSD_ao_css_include_inline',10,1);
function WSD_ao_css_include_inline() {
        return false;
	}

Hope this helps,
frank