Kobo browser not loading calibre

[howski]

Hi all,

Firstly sorry if this should go under the devices section I was 50/50. I run calibre web server and I've exposed it via a reverse proxy. Previously I've asked elsewhere and have been told that I'd be able to load up my library fine and download books on to a Kobo if I got one (I currently have a Kindle but might switch and this is the main reason as its broken on Kindle).

Recently a friend of mine recently got a Kobo Clara BW, so I thought it'd be a good chance to try it. I've added them as a user and all the normal bits however when they try and access my site they just get a blank page. I have had them try just the normal URL and the mobile. They have also confirmed that the URL works on other devices on their network and also that they can load different web pages on the browser.

Any idea whats up?