To program NRPN you need to assign the knob / slider to CC134, then setup MSB value (double push the button) then LSB value (double push the button). You need also set up proper midi channel for this knob / slider.
Eg. for NRPN message 1:9 (delay feedback which is also on channel 16) you need to:
Over the last few days, I’ve been playing around with the controller a lot and have created some mini guides for reference on mapping and other related things.
You said it was old and faulty. What was the fault? I have a UC-33e that fairly constantly sends out random CC changes on whatever knob was touched last. I’m guessing maybe filter cap issues in the power supply?