Password Protection Disrupted

I installed SpeedNinja to help with my mobile speed and the minute I installed it the password protection I had on one page immediately quit working. I use the standard WordPress page password protection to password protect one page with a single password. What happens is you are asked to put in the password and once you do so, it resets the password page and asks you to put in the password whether you enter the correct one or not. Once I deactivated SpeedNinja the password started working again properly. I’d like to use SpeedNinja but I need that password protected page.