Help please, I think I have RF or EMI problem

Hi everyone,
I really need help with your experiences.

My setup are :

Streamer : dCS Network Bridge
DAC : Chord Qutest
Pre Amp: Unison Unico PRE 
Power : Unison DM

Everytime I switch on air filter or certain light switch. It will create "pop" sound and sometime the music is "Muted". 
But only in certain area of the house.

I already fixed the grounding, and the resistance is 1.26 ohm.

The power cable is dedicated from the MCB panel to the system.

I separated the ground cable exclusively for my sound system.
But the problem still there.

I tried to move the air filter using different power source.
The glitch or the "pop" is gone, but if I move it closer to the the unit, I can hear the "pop" slightly.

Any thoughts?
Thank you so much in advance
Kind regards,
Nick