EV-ADF4401ASD2Z Evaluation Board's output is off frequency in Translation Loop mode

Hi Community,

I am evaluating the EV-ADF4401ASD2Z Evaluation Board and seemingly can't get the RF output to stay at the desired frequency in Translation Loop Mode. In Calibration mode the output is exactly on the target. 

The settings:

1. Calibration Ref - 10 MHz / +9 dBm.
2. External Reference - 10 MHz / +9 dBm
3. External LO - 4.5 GHz / 0 dBm
4. Windows 10, 64-bit OS

The software controlling the board is ACE v. 1.24.3095.1398.

The output signal in Translation Loop Mode sits at about 4.28 GHz vs 4.51 GHz in Calibration Mode.

Power supply is 6 VDC / 800 mA  from a benchtop U8002A by Keysight.

If anyone could reply with suggestions, I'd greatly appreciate it.

Thank you.

90125