Plugin settings

Hi
I have a site that is completely https:
The site was working fine onlt with some slow perfomance issues. I am using the Avada them and was recomended by their support to install the W3TC plugin. upon activation of this plugin some of my pages are broken apparently there are suddenly request from http which is causing this. The theme support recomended intalling your plugin which i have though the issue is not resolved and i dont know the reason.
Hope to resolve this soon
thanks

https://wordpress.org/plugins/wordpress-https/