Squid proxy server won't work with instagram, twitter, facebook, etc..

I've recently bought a vps for creating an Squid Proxy Server, all good untill I was trying to connect to social media sites, it's not working, for any other site is working but not for these..
I think it has something to do with https filtering and ssl certificates, but I can't get to a valid method.
Vps is using debian 8 jessie.

Could anyone help me?

Have you tried to check if the error is for https and not http?

How can I check that?

lukftw said:

How can I check that?

Click to expand...

Well, try to access websites using http and others using https