Ps5 audio with ps4 controller

This is also only an issue through the keymander2 becase the audio works fine when I take it off the usb

The PS4 controller audio is supported using PS5 and K2, but you must make sure to have Sound set to Controller Headset.

When I have the keymander plugged in it wont slow that option to set it to headset with the controller

I'm not sure why you cannot see the Sound menu, but if there is some issue then connect your PS5 controller to the PS5 console using the USB-C cable supplied with your PS5 console, and make sure to keep the PS4 controller connected to the the K2 unit. You can normally access settings with either the K2 or controller in this case, although I tested it using the K2.