jardah,
I added that code to my .htaccess, but no change. When I go into Chrome Inspect and look at what files are mixed content, they are nearly the same files. The files are part of our website, which is HTTPS.
https://www.edgeworksclimbing.com (our main website that hosts the mixed content files)
https://www.edgeworksclimbing.com/blog/ (our wordpress site that is trying to load files from the above site using http, so it is giving an mixed content warning).