Duo on Ubuntu sudo not working


I have setup Duo on Ubuntu 16.04 and got it working successfully. The problem that I have now is that sudo no longer works. I’m prompted for a local password when invoking sudo, and when I enter it, it says it is incorrect (the password is correct). I had confirmed sudo was working correctly before, but now after a power outage, I brought the system back online and I am still able to ssh successfully, but sudo is failing.