Are you seeing the "AMD High Definition Audio Device" in the Sound Control Panel, should look something like the attached screenshot. If yes is it set up as default and configured correctly? If not try powering off and on your TV and or AVR if you have one or as a last resort reboot to get it detected by your OS.
The above assumes you are using Windows, if that does not work please provide details of your hardware and software INFORMATION REQUIRED WHEN POSTING A QUESTION
EDIT :Finally I solved the problem.
I was right in saying that the cause of my problem was the AMD update. I'm back on version 18.5 and my problem is solved. My TV reappears well in my audio device.
Hoping that the next update resolves the problem
I'm sorry for making you waste your time. Thank you.