Okular bookmarks work stupendously and I make heavy use of them. I keep a mid-size number of open instances of Okular at all times with different books I'm reading atm. The problem is that after a reboot, all my bookmarks disappear, i.e clicking on the bookmark toolbar button shows nothing. Of course, the page I was last viewing is still active, but in reference books, in which I like to go back to re-read a specific section, this is annoying.

The only way to get my bookmarks back is to close and manually re-open the file, which, of course, wouldn't be a problem if I opened every book on each restart but I don't, I save my session on shutdown and resume it on login, so KDE opens the files for me.

Does snyone have any idea on what might cause this?
Using Debian stable, KDE 5.14.
Thanks.