Check if any of the following applies:

- Devices are logged into different AlphaTheta accounts.

Use the same AlphaTheta account on all your devices.

You can check which AlphaTheta account you're using on each device as follows:

rekordbox for Mac/Windows: MY PAGE

rekordbox for iOS: [Settings] > [Account Information]

- Cloud Library Sync is turned off.

rekordbox for Mac/Windows: On MY PAGE, open the [LIBRARY SYNC] tab and turn on [Sync library to another device].

rekordbox for iOS: Open [Settings] > [Account Information] and turn on [Cloud Library Sync].

- You're using LINK EXPORT mode.

Libraries can't be synced when you're using LINK EXPORT mode.

When you finish using LINK EXPORT mode, the library will resume syncing.