Hey guys, I saw the post on the front page today, and was pretty surprised since I have just started suffering from a similar issue a few days ago.
For a TL;DR: I think that changing the personal info on your account causes some alarm bells over at BSG to go off, and they lock your account.
But anyway, onto what happened.
I originally got the game about a year ago as a present from my brother. Unfortunately, he wasn't really aware that you could "gift" someone the game, and instead created his own account on the website to buy it (complete with all of his personal information). When I got the game, I had to use that account as it was the one the game was tied to.
Anyway, when I first got Tarkov, I wasn't really that into it. I didn't play it much, and didn't really like it. However when 0.8 came out, I figured I would give the game another shot and started playing again. I've been loving the game since then, and been playing almost every day. And seeing as I was actively playing the game now, I decided to finally change the profiles information to match my own (Stuff like birthday, name, in-game name, etc).
And then a day later, I could no longer log into my account. Tried resetting the password, username, nothing worked. Just kept getting a login failed.
So yeah. If you've edited your profiles information, it may have caused BSG to lock your account. If anyone from BSG can confirm if this is the case, i'd be happy to email you with plenty of proof in order to get my account unlocked(since i'm aware this situation does sound a bit far fetched).