QPSK Modulation Issues in ADRV9361_z7035

Hello

Hope you all are doing good.

I am trying to implement QPSK modulation on ADRV1-9361-Z7035. At transmission side, my signal is modulated correctly giving all four-phase transitions according to data pattern. But at receiving side I am facing two major issues:

1) When I transmit the sum of QPSK modulated signal through DAC in 16 bit I channel while on Q channel I tried transmitting same signal or constant zero on one channel and loop back  TX and RX using SMA cable and analyze the received signal at ADC, the Received signal shows irregular behavior when analyzed on ILA like at some instance it gives two of the phase transitions in I while other two transitions in Q but at other instance it shows all four transitions in either I or Q It is not showing a constant behavior though my LO frequency is fixed in all cases.

2) For Board to Board Communication I experienced amplitude attenuation like my signal bends at RX as in AM.

Can anybody suggest something regarding this issue please.

Regards