LNA gain stable but IP3 worse almost 20dB, help

Hi, all
I found a question when I test a board that the Gain of a LNA is unchanged but the power level3 is worse almost 20 dB when it parallel with a digital control attenuator by a hybrid, I can't image why a hybrid and a attenuator can change the power level3, is there anyone can give a idea?
thanks.

Possibly the attenuator is having lower IP3, check it

I'm not sure what you mean by "Parallel" with a Digital Atten.
But first test the LNA along at ~ 5-10 dB below it's -P1dB point.
The IP3 should be ok. If this is true then it is your setup.

I guess,
Its a block having two paths like LNA with bypass switch.
the signal is attenuated through the attenuator when the signal strength is high with a controller sensing.
the signal is routed through amplifier if the signal is week.
So these attenuator and amplifiers are in parallel.

Hi moringwind, share the schematic with the P1dB and IP3 values.