Ive been struggling for quite a few weeks with my problem (not an amature id say).
As seen in the attached pic, even though my PC recognises my TV in device manager, i cannot set the sound output to HDMI. Before the option went missing (like 1-2month now), i had no trouble as it WAS an option in sound settings.
Freshly reinstalled win10 64bit.
MSI B450M PRO-M2 V2 board
Asus r9 380 4G OC VGA
8G Kingston RAM
Ryzen 3 2200G CPU
High Defenition audio device; 10.0.18362.356 under "sound video and game controller", 10.0.18362.1 under "audio inputs and outputs".