Problem reading the RPD bit correctly when Auto-Ack is turned ON.

Using NRF2401+, I have two units running side by side on the bench.

With Auto-Ack turned OFF I can successfully read the RPD register (bit 0) and get the expected readings of 1 or 0 depending on the distance between the two modules.

However, when I turn Auto-Ack ON, RPD only ever reads zero even at very short range.

I am certain the issue is down to my code, and the point at which RPD is read. It is being read when the RX_DR interupt occurs. Any help will be most appreciated thank you!