Every time you move to offline document library (in PWA), it will auto-synchronize to check whether there are any new favourites to display or any favourites to remove. If there are any new favourites, it will be displayed with a Green dot on top of the folder/ document like below.
Note that you will only see the folders which you have made favourite (by self or mandatory) and have at least ‘View’ permission. Also, offline document library can be only used to view documents, you will not able to upload or modify favourites directly from offline document module.
