ADAR1000-EVAL Measurement result

Could anyone clarify and give me any advice?

Part : ADAR1000-EVALZ

We tested the method provided by the user guide.
Test was conducted using ADAR1000 Max Gain Settings provided by ADI web.
Based of Freq. = 9.5GHz @Tx1, the gain was 15.9dB. The board loss was 3.2dB.
The datasheet says 21dB.
can you advise me

Please kindly help.
Please. Can someone tell me?