Unpopulated playlists

I’ve been in touch with Google regarding my issue with my uploaded playlists on this app. Only 6 playlists out of over 200 contain art and music on either of my 2 iPhones . Yet, these exact same playlists are complete and playable on my iPad, MacBook, Windows laptop and Google Home Mini. In my case, this app does not play nice with iPhones. Very disappointed.

Me96775366 about Google Play Music, v3.38.1007