Problem is onn a Mac computer.

I guess you already reviewed the possibilities in this help article, but just in case:

Recover lost or missing Bookmarks

I have tried to restore bookmarks, but it only shows one option from August 2021, no sign of any automatic backups.

Were there any other profiles listed on the about:profiles page, or just the current one?

If you use the Time Machine or other backup then try to restore file(s) from this backup.

• https://support.apple.com/guide/mac-help/restore-files-mh11422/mac
• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

jscher2000, There are 3 profiles in Users and Groups in Preferences. 2 admins and a guest user, it does look like the right profile is being used. I tried unlocking and switching users but nothing holds.

cor-el, Time Machine says oldest backup is from October 22 2020, and Back up Automatically is checked, so that's good to know. But there's also a red i pop up that says: Time Machine couldn't complete the backup to "Untitled" the backup disc is not in Mac OS Extended [Journaled] format, which is required.