Siri incorrectly identifies songs as already in library on HomePod

I have been using Music, HomePods, Siri etc for years no problem but now when I ask Siri to 'add song to my library' that is playing on my HomePod the answer is always 'this song is already in your library' which it most definitely is not! (also not in a playlist that is not in library or in favourited songs etc). I have done all the usual resets and power cycles. Anyone else experience this glitch?

[Re-Titled by Moderator]