Thank you for this. I am connecting the radio panel using the X-Plane software. My wireless headphones are now connected to X-Plane and my radio panel is working properly.
I have moved to V11.30 and also changed the USB connection port on my motherboard. All is now good. I have found with FSX that it too can be quite picky about which port will work with headphones. I am now using a port at the back of the PC, previously I was using one at the front.