Power BI, Application Proxy and 'Resources' not showing

Hi
 
I have sucessfully set up Azure Application Proxy to our on prem Power BI report server. All is working apart from one scenario.
 
For some reason 'Resources', such as a PDF file, are showing up just fine in a desktop browser (even when going through the application proxy) but the entire 'Resources' section is not visible when viewed in either a mobile browser or the mobile power bi app. Is this a bug or a feature?

Thanks

Roger