4355-2 Phase Adjust: Integer-N

I am using two EV-ADF4355-2SD1Z boards to generate two RF signals.  I was able to adjust the phase difference between the two RF signals using the phase adjust on the GUI. But, this was only when N is frac.  I was unable to change phase when the RF frequency is an integer multiple of the REFin.  Could someone help me on this please? I have attached the setup I was using.  

[edited by: Gmicael at 12:11 PM (GMT 0) on 24 Apr 2019]