I'm testing the slow attack AGC mode of ad9364, I connected the upconverted waveform directly to my Receiver through SFU(Broadcast Test System). In SFU I can able to set the attenuation (in dBm) and for the default parameters setup in AGC of IIO Osc application, I'm seeing a Hardware gain of 4 dB less than my SFU attenuation and I'm also seeing phase changes in between the gain variation even though I used custom gain table with LMT gains varying. How can I avoid phase variation in between gain changes and what is causing these gain changes? Why am I seeing this constant difference between my hardware gain and SFU attenuation? How can I control it?