I had almost the same problem. But in my situation those bookmarks had appeared EVERY(!) time I wake my computer from hybernation. Once I thought, ok, fine. I won't remove them and just leave them on express panel in their own folder. But today I noticed one of them ran away from its folder. What the actual f...? Guys, it is not funny at all. I agree that you have to get money somehow (and actually do it with ads), but it gets really annoing.
I'd really appreciate if you look into this problem. I don't want to move to another browser, but you pushing me to it..