I'm on the beta program and in the UK. I asked Alexa to play BBC Radio 4 this morning and it said it couldn't. I asked Sonos Voice instead and it said the same. An Alexa device has no problem.

I tried on various Sonos devices and got the same response. I rebooted my Move 2 and it still couldn’t play. 

I opened the Sonos (beta) app and it asked to be updated and took me to the downloads page, but there is no new app to download. I tried reinstalling the existing version and it still insists on being updated.