The lyrics come from a company called lyricfind.com. Roon doesn’t create them. If there isn’t a lyric lyricfind hasn’t created one for the song and/or may not have the rights for them which have to be obtained separately from music publishers (not the music labels who put them on album or cd covers). Having run a company called gracenote for a decade who was the first to obtain rights to be able to display lyrics digitally, I know this space pretty well and it’s frustratingly complex.