This notice, “Your connection to this site is not fully secure,” usually shows up when your WordPress website has a Mixed Content Error. You may have an SSL certificate installed on your site, but also have script or content loading with HTTP. Thus, a mixture of secure and non secure content. This can have a negative impact on your rankings and cause you to lose customers.
The first thing to do is make sure that you have the SSL certificate properly installed on your site. After this, you can check the site to see where the mixed content is by using online tools such as Jitbit and Whynopadlock.
Also, if you right click on the page and go to View Page Source or View Source, you will open the code content of that page. Here, using control or command F, search for HTTP: and see where in the page you have non secure script or content.
Now if you want, you can manually change the HTTP to HTTPS, however, a faster and easier way to do this would be by using a plugin such as the Really Simple SSL Plugin.
Once you have installed and activated the plugin, from your WP admin dashboard, go to Settings and click on SSL. This will allow the plugin to detect your SSL certificate and begin changing your HTTP to HTTPS.
