You have been locked out on successful login

I’ve been using iThemes Security for many years now but lately, I’ve been trying to login and I do so with the same successfully used username and password, but I keep getting the following now after logging in.

You have been locked out.

You have been locked out due to too many invalid login attempts.

Why is this happening? Only way to stop it is to rename the plugins folder.

The page I need help with: [log in to see the link]