Viewing a meteor website through a proxy


I am having trouble accessing any Meteor - built website through an online proxy service.
I have tried multiple proxy providers and multiple websites built with Meteor, but none of them show any content added with JavaScript. Only HTML and CSS.

I myself want to test a website that is being built with meteor through a proxy to simulate different locations but all I see is an empty page when opening it through a proxy server.

Javascript seems to be enabled and I can show a message for cookies with it but no other content is being shown.

Does anyone have any idea what might be the problem ? - Meteor having issues with proxy servers or maybe the proxy providers themselves disabling/filtering out some content ?

Any help/comments would be appreciated!