Quantum has been around for quite awhile now. The first Quantum version was Firefox 57 (November 14, 2017) so a recent update shouldn't have caused this issue. A real update typically doesn't involve "importing" bookmarks or any other user data; the Profile is "converted" for the latest version automatically.

On the other hand, if you recently installed Firefox 68 anew, rather than updating, perhaps the new installation created a new Profile assuming that it was a 2nd version in addition to an old, existing version. That is a new feature in Firefox 68 where the user can have multiple versions of Firefox installed, each with its own Profile which is used automatically without user intervention.

What other data types are you missing, beyond bookmarks? Browsing History? Logins / Passwords data? How about old add-ons? Does the Addons Manager show a category that lists Legacy extensions? IOW, those that aren't compatible with Quantum.

Knowing that may help us determine if you have a new Profile, and how you should proceed fixing your issue.

garnetfriend01 said

I have them saved but tried importing them manually to no avail.

What exactly do you have saved? For example:

• JSON-format "backup" file
• HTML-format "export" file
• folder full of Favorites
• something else