Issues rolling out to debian 10

Hey Guys / Gals,

Having a few issues have rolled out duo to a Linux host (Debian 10) having issues so i run as per

Have skipped the Public Key / PAM configuration section as i won’t be using public key auth.

Have tested the auth and it works fine as per

sudo login_duo -f myusername 'echo "Hello World"'

and that works fine but when i change the 

/etc/pam.d/common-auth

from 
auth  [success=1 default=ignore] pam_unix.so nullok_secure
auth  requisite pam_deny.so
auth  required pam_permit.so

to 
#auth  [success=1 default=ignore] pam_unix.so nullok_secure
auth  requisite pam_unix.so nullok_secure
auth  [success=1 default=ignore] pam_duo.so
auth  requisite pam_deny.so
auth  required pam_permit.so

Open a new terminal putty session and try and login i get the revolving asking for password and not actually accepting the session or asking for 2factor. Rolling back the changes in /etc/pam.d/common-auth allows authentication again.

Any ideas?