Sometimes a completed workout from a device may not sync correctly with the corresponding planned workout. This can happen if the planned or completed workout was created with a non matching workout type, or if a workout was completed at a different part of the day than planned.
To rectify an incorrectly synced workout, open the workout that the completed workout was synced with and go to the "Sync" tab. Now use the Un-Sync button to remove the completed workout.
Now open the planned workout that should have been synced and again go to the "Sync" tab and use the manual sync options to sync the completed workout.
NOTE: If your sync tab does not show an option for manually syncing you can instead download the original workout file (normally a FIT) file from your devices training platform. E.g Polar Flow and upload it on the analysis tab.