Why do you have a 500K resistor in parallel with the capacitor?
What is the value of your volume pot?
I’m using 500k pots, and with a 4 conductor humbucker, the parallel RC is in series with the north and south coils.
With my limited understanding of electronic principles, I can’t tell you why what goes where, but I have followed schematics that show this configuration and placement.

I’ll post the drawing later. I’m away from my computer atm.