Page load via ajax – feed not loading

We have a site which loads new pages via AJAX (everything inside the body is wrapper in a div.outer, with the content replaced on loading new page via AJAX). jQuery is not used for the ajax call.

I have set “Are you using an Ajax powered theme?” in settings to Yes. (I’ve also tried setting it to No, no difference).

On initial load of the site the Instagram feed loads fine, but on loading a new page via AJAX the feed fails to load and looks stuck on loading (the loading animation is showing). There aren’t any javascript errors in the console so it’s as if the newly loaded content just isn’t firing anything.

Could you give me some high-level insight into how the feed loads when “Are you using an Ajax powered theme?” is set to Yes? I have tried to look at the code but I’m having trouble understanding it. I wondered if there is a javascript event I can fire to trigger the feed load?

Thanks in advance for any insight/ any lines of code you can point me to to better understand it.