When you replaced the moving coil meters on the output with a DVM you reduced the quiescent current through the MOSFET.
Try adding a 10k resistor between the positive output and the negative of C2. However a resistor will create a current that will vary with the output voltage. This is not ideal.
A better solution would be a constant current circuit.
Try adding a 10k resistor between the positive output and the negative of C2. However a resistor will create a current that will vary with the output voltage. This is not ideal.
A better solution would be a constant current circuit.