How to secure account after purchase?

I have purchased multiple accounts from different vendors on here and I don't know if this is an issue with the vendors or with the way I am using the accounts, but whenever I get an account, I wait at least one day and change the password + turn on two factor authentication. But even then, a few days later someone will somehow get access into the account and change the email compromising the account. How is this even possible with 2FA on? Let me know if you have any suggestions to really secure an account after purchase so no one else can get into it or reputable vendors where this won't happen.

need to ask from there seller to share method about managing the profile from getting suspend after purchase,recent reddit work perfect in some special locations without shadow ban.