Here is a summary of what happened:

• I had been using Opera GX with an active Opera account, and bookmark synchronization was enabled.
• A few months ago, I imported bookmarks from another browser (Comet) into Opera GX. These bookmarks were synced to my Opera account.
• Approximately one week ago, I had to reformat my computer.
• After reinstalling Opera GX and logging back into my Opera account with sync enabled, most of my bookmarks were restored, however, one folder
  containing links to scientific journals and research institutions is missing.
• I suspect that when Opera GX was reinstalled fresh, the empty local profile may have overwritten the sync data on your servers before the restoration
  could complete.

I would like to know if it is possible to recover a previous snapshot of my synchronized bookmarks from your servers, prior to the reformat date
(approximately between one week to one month ago).

Thank you very much for your help.