I have an Ubuntu Linux PC running a UPnP server that is visible to all devices on my network. However, VLC on my iPhone and iPad (3.2.13) and Apple TV (3.0.12) cannot see any of the media. The server shows up just fine but when I open the media server in the VLC apps, my Apple TV VLC says "Empty Folder" and my iPhone and iPad show the constantly rotating wait symbol. VLC on my MacBook (3.0.14) CAN see and play all the media content as can my Sony TV's native UPnP media viewer. To recap, VLC sees the UPnP content just fine on my MacBook but not on my iOS/tvOS devices. I can also report that the Apple TV app 8player can see the UPnP media with no problems.
Please help!