When you open your page in the Optimizely editor, the editor tries to load your page through proxy, HTTP and HTTPS. If HTTP or HTTPS succeeds before a timeout occurs, your page should load fine, since this will use your IP address. If HTTP and HTTPS timeout, and loading your page through proxy succeeds, your page will be loaded through a proxy server and that server's IP will be used.
What you could perhaps try to use is the Optimizely Editor loading extension. This should help with your loading issues.
I hope this helps!
Technical Support Engineer