We had hub issues that caused some stability issues, in line with this, we have enabled a feature in the hub that will block logins from someone that has done more than 5 attempts in 5 minutes. This applies to clients as well as internal users
Long and short of it is, if you find you can't access the hub anymore and you have been hitting the login page with invalid details you will get locked out for a bit. it's just a time-based thing so if anyone gets locked out, they just need to wait 5 minutes for it to refresh and then log back in again with the correct password.