Try using Tab Session Manager https://addons.mozilla.org/firefox/addon/tab-session-manager/ or Session Boss https://addons.mozilla.org/firefox/addon/session-boss/. They do not use bookmarks.
I do not use bookmarks, I did not know, and I could not assume that you would have problems with the search. About this, except for you, no one wrote to me.
Write to me about other emerging issues. I have neither the time nor the opportunity to fully test the extension.
Write to me in any case. I have thoughts on how to improve the search for bookmarks.