HDC2450 Pln5 and Pln6 issue

I have setup the HDC2450 with a 6 channel spektrum AR6000 receiver and Roborun reads no input on Pln5 or Pln6.
All connections appear good and Roborun shows the Dln5 and Dln6 flashing indicating the controller sees the pulses on the input.

I have obviously configured the controller to read the Pulses on Pln5 and Pln6 however it just reads zero.

All other channels appear to work fine.

Any update?