HomePod not playing BBC World Service via Siri due to Apple Music error

HomePod plays other streaming radio stations, including NPR radio and used to play BBC World Service but stopped recently with the same message coming back from Siri: "sorry there was a problem with Apple Music."

I can manually connect my iPhone to the HomePod to play BBC World Service but I can't use voice command (using Siri) to get the HomePod to play it which is frustrating. I have two HomePods in my home and both give me the same message.

Any suggestions please…

[Re-Titled by Moderator]

Original Title: HomePod no longer playing BBC World Service, saying there is a problem with Apple Music. How do I fix this please?