playlists

No idea. Not enough info to have a chance of knowing.

Btw, thanks for your contribution here

For me, it’s because I wasn’t wearing my glasses.  

Doubt that’s the issue here though.

Perhaps this will help me get an answer. I have a few thousand songs on my hard drive. I’ve added them to my Sonos music library. I have selected a certain number of them and added them to a Sonos playlist in the PC app. I can call up the play list on the PC easily, but not on my Samsung S10. What other information can I provide?

That makes things a lot clearer. On the phone, go to My Sonos (the star far left on the nav bar). Scroll down to Playlists. Tap the word 'playlist'.

Are they there?

This update will work, but there is another solution. On an iPad and possibly on Android, Playlist updates and new Playlists will not appear until the Sonos app is shut down and reloaded. On an iPad, swipe up halfway and pause. The apps that are open should all appear. Find Sonos and swipe up to get rid of it. Then reload it. I found this is true with Primephonic streaming service and there will be others too.