Brake issue on one wheel only

I’ve run into an issue that I’m having problems solving:

I’ve got a helicopter with a tricycle landing gear arrangement. Brakes are configured just as they would be on an aircraft, with left brakes on left wheel, right brakes on right wheel. Parking brake works, and from the debug window, I can see braking input being supplied to wheel #2 (point.1) and wheel #3 (point.2), as it should. point.1 & point.2 in the flight_model.cfg file are identical, other than the left/right offset.

However, from the debug window I can see that individual left / right braking is only working on the left side, NOT the right. The hardware pedal inputs are working (on other aircraft & on the control inputs assignment UI).

Any thoughts as to why it would work on one side but not the other?