The problem is quite obvious once you look at Bookmarks.html:
{
"date_added": "13229856088561651",
"guid": "3d27066e-a44a-45f1-90e3-…",
"id": "26670",
"name": "…",
"type": "url",
"url": "https://…"
}
There is a date_added
but no date_modified
. Only the folder have a date_modified
. That way Opera only knows when a folder has been modified but not what has been changed inside the folder.
I have not seen and date_deleted
at all which would explain why deleted entries reappear all the time.
I consider that a design error which are the hardest software errors to fix as you need to redo the design.