All BBCs have gone from the tunein app, bar world service and BBC Wales, so in my Dad’s case when setting up the stage we couldn’t add the likes of radio 2 and 4 as favourites for the B&O app to use. I suspect if I removed bbc from my favourites in tunein they’ll be gone forever from my essence and play M3.
Are you comfortable setting up a Raspberry Pi? I'm using one with VLC and IceCast to receive and re-stream stations that aren't available on TuneIn due to some similar issues in the States. It works flawlessly, and is fairly inexpensive to set up. I'd be happy to provide guidance if you have basic comfort using Linux/Unix/Raspberry Pi.
My B&O Icons: