Interfering With Admin Log-In

Redirection for users works fine. However, when I log-in as administrator via the WP panel, my password only works one time. After that, when I try to log-in, my password disappears from the password box. There’s no error message. If I reset the password, I can log-in but, again, only one time. If I deactivate the plug-in, I can log in-and-out over and over again.

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