Why does it sometimes show that my website is not secure even though I have an SSL?
An internet browser will sometimes indicate that while a website itself is covered by a valid SSL, not all of the content on the page comes from a secure source. This most commonly happens when a web page is displaying images or other content that is hosted by an external website.
To prevent this from happening, try to host all of your website’s content on the same server that your domain is pointing to. If this is not possible, you can consider designing your website in a way that only the critical web pages are covered by the SSL (such as the pages where you are asking for credit card information) while the remainder of the website remains uncovered.