Inline and Defer CSS

the problem is that you indeed can (try to) inline parts of it as critical CSS, but the contents of “?wpcss_action=show_css” will not be autoptimized (as it’s not static CSS) so it won’t be deferred so it remains render blocking.

if you really want to solve this, you would have to try to get rid of that non-static CSS somehow (guess it’s inserted by a plugin).

hope this clarifies,
frank