Latest version of FF. Using Win11 on a modern desktop PC. This is the first time this ever happened; fortunately I keep an updated local copy of my bookmarks on my NAS. Just started happening today. Both my W11 and W10 machines suffer the same malady. So it appears to be a FF issue. I restore my corrupted bookmarks from my NAS, but as soon as my PC syncs, they are all corrupted again. It's like one of my bookmark folders absorbs all the bookmarks from sync as one long mixed up list. Anyone else having this issue? If so, is Mozilla aware of the issue?