Help with KNOB + CV on one ADC Daisy Seed

Hi there,

I need some help getting this schematic to work. i want the cv input to be added to the knob value as is to be expected from the schematic but i am getting odd results.

Is there anything i am missing or a resistor value that needs changing? i am getting around 0v from the output, i think the connected cv input is maybe clipping the op-amp to that value but not sure. thanks in advance!

:)))) much help much appreciated.