This is typically an issue with SSL termination at the edge (AKA Flexible SSL.) The problem is that you're making request for http assets on an https page. Most modern browser will block these request from loading for security purposes. You can fix this by loading your assets relative to the protocol (HTTP/HTTPS.) The files path would look like this:
Great read on this, The Protocol-Relative URL.
Depending on your CMS, there may be modules/plugins to do this for you automatically.
If you're not sure this is the issue you're having, you can open up Dev Tools in your browser and view the console tab. The error may looks something like this:
Mixed Content: The page at 'https://domain.com/' was loaded over HTTPS, but requested an insecure resource 'http://domain.com/path/to.file'. This request has been blocked; the content must be served over HTTPS.
- You can fix this by adding the relative protocol
- or install a certificate on your server and use the full ssl option.