I use Steam as a login session in a HTPC based on LinuxMint 20.1, based on SteamOS (steamos-session). I find that when I start Steam in BPM, sometimes the audio does not connect. The remedy usually seems to be to log out of the user session and then log back in.
On a login when you dont get sound, I find that the audio interface is initially unpopulated, and when I cycle out of the audio interface UI and then back into it, the interface dropdown sometimes doesnt contain the HDMI device sinks, or if it does it still wont actually connect to the audio source when you pick it.
Your system information
I use Steam as a login session in a HTPC based on LinuxMint 20.1, based on SteamOS (steamos-session). I find that when I start Steam in BPM, sometimes the audio does not connect. The remedy usually seems to be to log out of the user session and then log back in.
On a login when you dont get sound, I find that the audio interface is initially unpopulated, and when I cycle out of the audio interface UI and then back into it, the interface dropdown sometimes doesnt contain the HDMI device sinks, or if it does it still wont actually connect to the audio source when you pick it.