When I synced multiple devices using Cloud Library Sync, the same track showed up twice in the track list.

You can select [Tracks stored on the computer] or [Tracks stored on other devices] in the Cloud column to remove unwanted tracks by filtering them.

Syncing the same track on multiple devices with Cloud Library Sync after importing the same track on each device results in duplication. You can determine which device the track is from by filtering by [Tracks stored on the computer] or [Tracks stored on other devices] in the cloud column. Then you can delete the tracks you don't want.