After deinstallation of the firefox snap I lost half a year of bookmarks. According to mozilla, firefox is supposed to create backups of the bookmarks and store up to 15 of them. Those are half a year old as well.
On examination, I suspect (but I might be wrong) that they were stored in ~/snap/firefox/common/.mozilla/firefox (I would have expected them in ~/.mozilla/firefox).
Now I wonder: Why would snap remove user data when removing (not purging) a software?
The folder ~/snap/firefox/ is not empty but ~/snap/firefox/common is gone. Is there some place where I could look for a backup.