All your values look to be correct can’t see R8 and 12
It may well be the intricacies of this circuit the eq is passive so you cut rather than boost frequency unlikely though
When you say volume drops is it just when you turn treble up and do you adjust volume to compensate if so does it work
As you can see from the schematic treble output goes straight to volume input lug 3 and out to your amp via lug 2 or dumped to ground via lug 1 depending on whether you turn it up or down
You may not get accurate readings with it in circuit but check with no power to the circuit if the volume pot resistances change turn it all the way down and you should have a smaller resistance between lugs 1 and 2 and higher between 2 and 3 and visa versa
I’ve not built this circuit yet so perhaps one of the guys that has can let you know it’s behaviour
Barry advises in the build doc controls section to set all eq to the middle and adjust volume etc from there