LoopbackExempt in UWP apps

In Windows 8.x, we had a LoopbackExempt thing that allowed Windows Store applications to interact with the local system for development purposes.
This seems to still be present in Windows 10 for UWP apps.
However, adding the release doesn't work (my apps still can't talk to localhost).

Executing CheckNetIsolation gives no results or results:

PS C: \ WINDOWS \ system32> Debug CheckNetIsolation -n = 5bd19b2a-6c63-4dd4-9505-d13f72e46189_ggxdvrfmnj0tt

A network isolation debug session has started. Play your script, then press Ctrl-C when done. Collecting logs .....

Consolidated report

Status of network capabilities

InternetClient                Not Used and Insecure

      

        
        
        
      

    

Detailed traffic report

InternetClient                Not Used and Insecure

      

        
        
        
      

    

Did they change anything regarding isolation for UWP? Is the article for enabling loopback exception still relevant to Windows 8.1?

Thanks in advance!