Lately I have noticed that my playlist are not in sync on multiple devices (iOS, iPadOS, tvOS). When I delete or add new movies to my current playlists, they are not updated in other platforms. I use OneDrive as cloud streaming.
Can you check to ensure you have some free space available in your iCloud account?
A few other requirements to check can be found in this guide.
Yes, still 30GB available. It seems that every other requirements are ok too.