You need pull-down resistors on the digital control inputs of your electronic switch, otherwise the logic level with switched-off S1 is undefined, so you don't switch between active mode and bypass mode, but between active mode and anything-can-happen mode.
U7B is not connected as an attenuator, but as an amplifier with a gain of 1.33.
U8B is not connected as an inverting amplifier, but as a non-inverting amplifier with a gain of two (hint: swapped wires).
I'd move the electronic switch to the output side. The way it is connected now, you get a voltage division between the microphone and the op-amps when you try to put the circuit in bypass.
INA333 is quite noisy, as mentioned.
Are the op-amps TL082 or TLV2462?
U7B is not connected as an attenuator, but as an amplifier with a gain of 1.33.
U8B is not connected as an inverting amplifier, but as a non-inverting amplifier with a gain of two (hint: swapped wires).
I'd move the electronic switch to the output side. The way it is connected now, you get a voltage division between the microphone and the op-amps when you try to put the circuit in bypass.
INA333 is quite noisy, as mentioned.
Are the op-amps TL082 or TLV2462?