BBC iPlayer Radio feeds



I have Plex set up on a QNAP and Roku is used to stream to my TV. Streaming of the video/TV channels works perfectly. However, I can't get the radio channels to stream. When I select a radio channel, it kicks me back to the main Roku menu and out of Plex.
Now, if I login to the Plex server using a web browser, I can go to the channels directory and can play BBC radio channels on my PC.
Have you seen this issue before?