Subfolders not syncing

I have already posted about this issue 2 weeks ago and have had no solution although my question is marked "Completed". So, here I try again.

Dear Madam/Sir, 
After a long break, I decided once again to store some content on http://Box.com and and sync it with my local folder. Unfortunately, I encounter a problem:.

The structure of my local Box folder is:
Box - Folders  - Subfolder (Level 1) - Subfolder (Level 2) - Subfolder (Level 3)

In my local folder, at the top level, there are 6 folders. Among  these, 2 folders contain  3 subfolders that should be exact copies. One  copy of this folder appears to have synced correctly. The other copy,  however, is problematic: not all subfolders at Level 1 have synced.

Specifically, please compare the number of subfolders in CALIBRE-CurrentCalLib (63) with the subfolders in OLD Calibre - Calibre Library (193). Same with subfolders Keep CalLib and Romanian CalLib - they also have a different number of subfolders.

Worse, the subfoders that  have not synced have disappeared - these folders and their data is lost.

I can only congratulate myself that I have made a copy of the Level 1  folder, otherwise I would have completely lost that content!

I would appreciate an answer and an explanation as soon as possible. Thank you,

ML - The account is under