This has happened to me a couple times, and manually recreating the playlists is quite a chore.
Here is a github repo that explains why this happens, and has code to create a new working playlist from the old broken one.
Moderator edit: Link removed. Search Github for “sonos-playlist-rebuild”
+18
+24Export them to SoundIIZ then re-import them, using tools that the Mods will not let me post links to. Search the web for “sonos soundiiz export” and you should get the info.
Amazon changed their url schema, so you need to re-create them from the artist/track names.
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