Drive fails to re-sync contents of document with Folderish and Collection facets

Steps to reproduce:

1. Create a custom doctype with both Folderish and Collection facets by extending Folder doctype and marking "Document is a Collection" (named "CustomFolder" in local testing). In JSON export facets should look like the following:

"facets": [
        "DriveSynchronized",
        "Folderish",
        "NXTag",
        "Collection",
        "NotCollectionMember"
    ],

2. In Web UI, create an instance of CustomFolder and enable Drive sync by clicking nuxeo-drive-sync-toggle-button from Document actions bar in top-right
3. Add sub-folders / content inside this folder using Create/Import 
4. Verify the CustomFolder and its contents appear in local directory
5. Unsynchronize this folder from Web UI; verify the folder disappears from local
6. Add various sub-folders / content to the CustomFolder instance
7. Synchronize the CustomFolder again using nuxeo-drive-sync-toggle-button

Expected result:
After re-synchronizing the CustomFolder, the folder and its nested contents reappear in the local Drive sync directory.

Actual result:
The CustomFolder reappears in the local Drive sync directory, but its contents are empty (any content added from Web UI after re-syncing successfully appears in local).