Uploaded files don't appear on the page
So after a lot of digging, I realised that this issue was due to the Panels module.

I had only added the field the usual way you would; through the content type when it turns out you need to configure it through the Panels view (which I was completely unaware of until today). 

You would think that configuring it though the content type would be enough but evidently not.

Nonetheless, hopefully my question and answer will come in useful to someone one day who encounters a similar issue to mine.