Encoder issues

This could be due to a badly seated encoder cap - on the side of the knob you will find a small brass screw. Loosen it and you will be able to remove the cap from the encoder.

Check if the encoder underneath is working as expected. If so, simply place the cap back on, but place it a bit higher on the encoder shaft than it was before - the reason it isn't consistently clicking/turning is likely because the knob is seated too low or loosely. Make sure to tighten the screw properly.