Solution found — This problem can be overcome by going to the Captcha Bank “Blockage Settings” and disabling the “Auto IP Block” setting.
For some reason, Captcha Bank was counting failed “login” attempts when there were no failed login attempts. As a result of incorrectly counting login actions as failed login attempts, Captcha Bank was automatically blacklisting my IP address as soon as I logged out of WordPress.
Whitelisting my IP address did not resolve this problem. Turning of the “Auto IP Block” option appears to have bypassed the problem since Captcha Bank is no longer counting what it thinks are failed login attempts.
Serious bug in the software to count failed login attempts when there were no failed login attempts.
