As of today I continue to get a count of 37 insecure references.
31 of the 37 insecure references I mentioned are for Scalable Vector Graphics (SVG) pointed at http://www.w3.org/2000/svg.
These references are valid as pointed out by @JuergenAuer, verified at https://www.w3.org/TR/2011/WD-html5-20110525/namespaces.html and
should not be altered.
If, as you stated, your WordPress general settings and permalinks are correct, then grab a good text editor and search your template for http:// (that don't point to "namespace resources") and replace them with https://
In any case, you have your LE certificate and it is working.
Please contact https://www.8theme.com/ if you need additional support with your theme
OR https://wordpress.org for support with your CMS, if required.
Of course, this forum always supports issues that are directly related to LE certificates, renewals, etc.