Receiver Spurs

I am testing a direct IF rec linearity and out is quite linear to input power but spurs start to apear even 6 dB before the compression point which stage is saturating before

Is it due to insufficient shielding?
try covering your receiver circuit with some metallic body and check.

Is spur not appearing at lower inputs?
Which point you are measuring?
Explain the schematic.

I cannot do anything about sheiding beacuse its chip but i can vary the power supply of different stage in IC by programing like supply to IF filter LNA and LO so which can effect most to reduce these spurs.

I am measuring at I Q before ADC and yes when input is low spurs didnt seems to appear

Will you explain the block diagram?
May I know the reason for IF filter having supply?