Problem with MPC subroutine to implement proportional loading (i.e. stress ratios constant) with *ORIENTATION feature in ABAQUS.

I am using an MPC subroutine to implement proportional loading on a cubic RVE. This subroutine serves the purpose of keeping stress ratios constant (<0.8% error) if I don't use *Orientation. But once I add  *Orientation feature in the input file, the subroutine fails to keep stress ratios constant (>23% error). 

Note: I am defining the material orientation triad along the triad of cubic RVE.