Torii facebook flow broken in iOS webapp?

I have an app with FB ouath login using Ember Simple Auth and Torii.

I use FB oauth flow.

In Safari all is well. When I add <meta name="apple-mobile-web-app-capable" content="yes"> to my HTML and run the app from the ios homescreen the login flow never completes and I'm stuck with a blank page. Please note that it all WORKS in safari.

I've read a lot of (old) posts dealing with this issue but I can't get it working.

I'm interested in:

1. What's causing this difference in behaviour?
2. A solution :)