Hi.  I am using Alexa to play BBC stations but you have to set it up right.

What is ‘Lounge’?  An Echo device?  I assume you mean you have an Alexa group with the Lounge Echo as the Alexa device and a Sonos Five as the speaker?  What is the Five called?

Have you installed the BBC Sounds skill for Alexa?

I assume you don’t have the Echo connected to the Five’s line in?

I might as well just explain my setup in one room, as it works fine for me.

Sonos skill for Alexa and BBC Sounds skill for Alexa enabled.

Echo Dot named Dining Room Echo

Sonos Play:5 named Dining Room

Echo Dot is NOT connected to line in

Alexa group set up with Dining Room Echo as the Alexa device and Sonos Play:5 ‘Dining Room’ as speaker

Required command is ‘Alexa, play BBC radio 2’.

If you specify the room - either Dining Room or any other room, it won’t work.  As I only ever want to start music in the dining room when I am in the dining room, I don’t find this a problem at all.

I have identical setups for Living Room and Bedroom.

I am not confident about the explanation, but I think the origins lie in the BBC’s withdrawal from TuneIn (which Alexa uses), and so you are essentially using the BBC Sounds skill for Alexa.  This doesn’t have a clue what you mean by ‘in the Lounge’, so it goes haywire.