If you are receiving a hard or soft fail due to mixed content warnings, then this issue lies with your website’s code itself.
A mixed content error occurs when there are some resources or links within your website that are loading insecurely or with http instead of https, stopping the entire page from loading securely and applying your SSL certificate properly.
You can test what links are loading insecurely by using whynopadlock.com or by pressing the following in your local browser:
Google
Windows: F12
Mac: Cmd + Opt + I
Firefox:
Windows: Ctrl + Shift + I
Mac: Cmd + Opt + I
Safari:
Mac: Cmd + Opt + I
Microsoft Edge
Windows: F12
One way to get this fixed up is to use a plugin called “Really Simple SSL” if your site uses WordPress.