I apologize for going so far off topic, but you might need to know and want to do something about it.
I've been using Mozilla Browser products for many years, mainly because of the convenience and permanency of Bookmarks. It appears that's all changed, now. In the latest Firefox browser, if you bookmark a site, it is added to a list called "Recently Bookmarked", but this list is limited to 10 entries, and a new entry bumps off the oldest entry. There's a History list, but that also seems to be limited as to how far back the entries go. You cannot set the sizes or properties of these lists, either.
I back up my bookmarks every once in a while, and each time in the past the size of the backup file has increased a few to as much as 12 percent. However my latest backup file is 44 percent smaller than the previous one, each time, using the "Export HTML" function, and I rarely delete a bookmark. Where did the missing bookmarks go, and why? If I use the latest "backup" command, the filesize is 57 percent smaller than the previous one done the old way, which makes me wonder what else gets lost in that new process.
Why should Mozilla care what we do with bookmarks? It's our computers that get overloaded - - not theirs. And how overloaded is a 3.6MB bookmark file? - - which is the size of my backup before they decided that bookmarks must disappear in the night for mysterious reasons. I guess they want us to start shopping for a new browser. If you care, tell them. I did, but have not heard back.