October 02, 2019
Brute Protect settings within JetPack add security against malicious login attempts. Occasionally, these settings can lock the login page completely, even with your IP address added to the whitelist.The best way that I’ve found to resolve this issue, and unlock the login form is to add JetPack settings to wp-config.
JetPack will show you an IP address in the error message (on the login form), copy this IP.
Place the IP in this snippet in your wp-config.php file:
Save, and the login form will be unlocked!