The problem is that autoptimize inlines the styles before the meta tags and sometimes when the inlined css is too large facebook can’t properly read them.
The solution is a small code sniplet that inserts the inline css after the meta tags. This code sniplet needs to be added into a child theme functions.php file.
add_filter('autoptimize_filter_css_replacetag','fix_css_replacetag',10,1);
function fix_css_replacetag($replacetag) {
return array("</head>","before");
}
If after adding this code there is visual problems, check your custom css and place it inside child themes `style.css` file and that should do the trick.
If adding code sniplet is too hard for you you can use this plugin