After upgrading my Windows 10 64bit OS with a R9 290 to 16.4.2 this morning my HDMI audio now only works when in stereo mode. I get no sound when in 5.1 mode unless I set the audio output to 24bit, 192000hz then when I run the test I get perfect static on each speaker test, but only ever just static. In 16 bit, 48k or 44.1k I just get silence . It's plugged into a Yamaha surround sound receiver and it lights up in stereo mode when the AMD HDMI Audio is in stereo mode and kicks over to 5.1 automatically when I set the AMD HDMI Audio to 5.1. I tried a new cable from the computer to the receiver, from the receiver to the TV, power cycled everything, no change. When set to stereo mode the audio works perfectly.
I called AMD and they said to try using the ati clean utility and re-installing 16.3.2 which I did, and it made no difference. I even tried 15.12 and 15.7 and same problem with both. By the time none of the drivers worked tech support was closed when I tried to call back.
This is my media center PC, it's really killing me watching everything in stereo instead of 5.1.
Let me know if you have any ideas.