Domain Mapping & SSL Issues on MU


I have bought a multidomain SSL certificate and successfully installed on my VestaCP VPS.

I have a wordpress multisite installation with 5 sites currently. I have been trying to force HTTPS with Domain Mapping plugin. I have also installed the "SSL Insecure Content Fixer" in order not to have mixed content over HTTP.

I have activated in the domain mapping plugin the following:

1. After activating that, some webs doesn't load the HTTPS securely, even having the SSL Insecure Content Fixer.

2. Also, some webs are having problems, while others not: .

3. And also, my subsites, are not loading in the frontend the pages in HTTPS... What must I do?

Please note: I am running my sites over Cloudflare, I don't know if it matters or not...