I can’t promise this will solve the issue, but here is a tip if you can’t login TO FTP because of too many failed attempts on your FTP account but you are sure you are the only one using the FTP and you are sure the password/account is secure (the best way to be sure is to change the password).
What I found when I couldn’t access my FTP using Filezilla with my hosting account was that it wasn’t because of too many failed logins, well it kind of was, but it was in fact MY fault. I had turned up filezilla to the maximum number of simultaneous transfers because I was uploading a large complicated website to the server.
What I didn’t realise is that my hosting company restricts the maximum number of concurrent connections to 7 and I had set filezilla to 9 simultaneous transfers. What I didn’t know was that filezilla was opening multiple connections to achieve the simultaneous transfers. After it had opened the maximum of seven, the server started denying connections. But filezilla continued to dutifully try and login again and again automatically, constantly failing. After enough of these failed attempts, the web server blocked my FTP account for too many failed login attempts.
So, if you suddenly can’t access your FTP account because of too many failed login attempts, the reason might be that you somehow (and not necessarily the same way I have) might indeed have inadvertently tried to login too many times.
I solved it buy dropping down the number of simultaneous transfers to well under my limit and waiting until the login ban was automatically lifted after a few hours.
Since then I have never been locked out of my FTP because of too many failed login attempts.