Ember: app not being fetched by Google

Having tested a simple (hello world) app in ember a few months ago, I was really excited because I knew that Google was able to fetch and therefore index it. Another app I built in Angular a few years was also being indexed! So I pressed on with my ember development and now have an application ready to deploy. This uses a PHP/MySQL backend api.

Today, I uploaded the production build to a server and then checked things in webmaster tools using the fetch and render tool. This time, nothing is being rendered !!!! I have double checked and uploaded the hello world app to the same server, which was fetched and rendered without any problem. I have absolutely no idea why this is happening!

I then looked at ember-cli-fastboot (having not really worried about it before because I thought that Google could index single page apps) and when I run

ember fastboot --serve-assets

I get

jQuery is not defined
ReferenceError: jQuery is not defined

So I'm now at a complete standstill after a lot of work!

Any help in resolving this would be much appreciated! Ideally I don't want to have to use fastboot, but if I have to, I'm not sure how to resolve the above issue.