Seeing the same thing after just buying my first Sonos boxes. Not being able to just play the playlists I have on my phone (that I use locally on my phone while travelling) means I’m unlikely to buy any more.

You should be able to do this. What make and model of phone? Which music player app hsve you used to create the playlists?

Google Pixel 3. The playlists work just fine in Rocketplayer and every other mp3 player I use them with, just don’t work with sonos. I create them in python from my itunes db.

I think as SONOS users update to Android 10.5 they will find that Google have Nuked their "on device" playlists from high orbit. https://support.google.com/android/thread/24235979?hl=en

Only RocketPlayer seems to be immune to the change for me. I tried a couple of other players after my SONOS fell over and none of them can now read playlist files with paths in them.

All I can come up with so far (just in case it helps others):

1 Connect Phone to a PC. Search for *.mp3 and *.m4a (or whatever extensions you use) where all your music files reside, which in my case is SD card\Syncr\. Select all the results each time (CRTL-A). Paste all those files to a folder on the PC. Repeat for all other extensions you want to use.

2 Create a new folder on the SD card or phone such as "TEMP SONOS" under the Music folder.

3 Select all (CTRL-A) files in your new PC folder (a ton of .m4a and .mp3 files probably) and copy to \MUSIC\TEMP SONOS\ folder on the phone.

4 Using notepad on the PC copy off one of your existing playlists (mine are stored in SD card\syncr\) and after editing it save the playlist to a new filename to the TEMP SONOS folder on the phone. It must be directly alongside all the media files. REMOVE all path information from that .m3u text file. ie it should look similar to this in Notepad or a text editor when complete:

#EXTM3U
19 All Kinds.m4a
01 All of the People.m4a

etc...

This is inefficient and if you have thousands of items on your playlist will need a script or macro to keep only the line content after the last slash. But if paths no longer seem to work in .m3u files (with various Android media players including SONOS) this process at least got me working again for now with my main playlists.
 

Mine worked fine when I first bought my Sonos speakers and downloaded the app….then same thing...I can see everything else on my device through the Sonos app except for the Playlists….I’m using a Samsung S8