Siri can't find new playlists in Apple Music

I have an Apple Music subscription and primarily access my music library using Siri through my Home Pod speakers. For some reason Siri can't recognise new playlists I've created manually in Apple Music saying simply " I can't find blah blah playlist in Apple Music". I thought Siri/Homepod/Apple Music integration was meant to be the main advantage of signing up to the Apple 'monoverse'. Does anyone have any ideas why this is no longer working?