I *think* the limit on max login attempts is being checked globally which is wrong obviously. SO one bad user can bring the site down.
I simply disabled the brute force check (not good, I know) to bring my site back up.
you can edit the ad_integration.php and find “check for max login attempts” and just above it, reset the variable to “-1”.
I tried setting this value from admin panel settings (default was 3) but was unable to do so.