Running your 3D secure 2.0 testing and see same results here https://developer.moneris.com:3000/3ds2
Using the test cards from here https://developer.moneris.com/More/Testing/Testing%203D%20Solutions
Test cases 2,3,4,5 are supposed to return Status of N,A,U,R and ECI of 7,6,7,7 respectively. Instead they are all returning Status of U and ECI of null