UK Tunein radio stations no longer working correctly on HomePod - "not in your Apple Music library"

I have used all three HomePods to play various radio stations available via the TuneIn integration.

However, for the past few weeks a number of stations which were and ARE on TuneIn now fail to play when commanded by commands that have worked for years. Randomly across three HomePods.

E.g. "Hey Siri, play LBC radio" - the response is "LBC is not in your Apple Music Library".

All HomePods have same and latest software, but the misbehaviour can be random on one or more HPs.

What I have found is commanding "Hey Siri, play LBC 97.3 radio" causes the errant HomePod to play the station. yet TuneIn lists the station precisely as "LBC UK" - but using LBC UK does not work as Siro reports "LBC UK is not in..."

LBC 97.3 is bizarrely an old name for the station.

Equally "Jazz FM radio" is not recognised, with Siri reporting back "FM is not in your..." so Siri is dropping recognition of the word "Jazz"!

Something is coming unstuck with Siri/HomePod/HomeKit/TuneIn integration. This has worked for literally years.

Anyone have a solution?