first sorry if bad english.since last week, firefox "forgets" almost every login i made (with exception of facebook and google so far), sites like youtube, gog.com, steam, mega and reddit, that are the most i used to browse aren't remembered anymore, also my browse history disappears.i've checked the security and privacy tabs from options menu and all is in order; Firefox's delete history when it closes it is unchecked. And Firefox's remember sites is checked.I am the only one who uses this laptop, by the way.what can be the cause of this?