Performance report re Smush Pro and leverage browser caching

My performance score hasn’t budged since yesterday despite engaging WP Smush pro – which maintains it has optimised my images by 188mb. My Leverage browser caching rating also doesn’t seem to have moved in spite of having fixed a server error that was preventing it from working. I also note that my site’s ranking, according to a third party ranking checker seems to have deteriorated since I started to use these features and make some recommended changes. I appreciate ranking isn’t a straightforward relationship with a narrow set of conditions, but the coincidence is of concern