i guess i was hacked too i recently gained 3 groups of l2 content with one of them had 8k people in it and i am admin now in all of them, i shaped them a little and voila $$$$ gifted
i dunno if it was hacker or facebook mistake i have those for some months now without any issues
the only thing you should be aware is that your connection is done safely to facebook if you are stealing internet or some unknown network is used, all this chat with meta could be malicious too, using proxy can also be the reason of what you are going through. leaks dont happen like that, you did a mistake, or like my case you were unlucky no matter how safe you were.
PS: i had to drop the other admins because highlander rules, there can be only one.