Problem with ADRF6720 Eval Board

We bought two of the ADRF6720 Eval boards for a demo preparation. When we are
testing the boards we noticed that through the USB control, we set the RF
output to be 2.5GHz and on the spectrum analyzer we observed 2.1GHz. This
frequency offset is constant for different RF output values. I also checked the
LO port, also LO port has 400MHz offset. I read the user guide of the eval
board but I couldn't find a way to fix it. Can you please help me to solve this issue?

Thanks!