While Valve continue working towards the public SteamOS 3 release for more devices, and we've seen them note work towards that in the initial SteamOS 3.7 Preview, they continue rolling out more bug fixes for the Steam Deck.
The latest "SteamOS 3.7.2 Preview: 2 Safe 2 Sound" release is available with this fix:
General
Fixed a sound crash on session switch on Steam Deck OLED
Source: Valve
Since this is in Preview you need to manually opt into it via Settings > System > System Update Channel. SteamOS 3.7 is a big update but it's not reccomended if you want a properly stable experience.
One annoyance I've encountered so far is that all input seems to randomly break sometimes. On both the Steam Deck itself and external controllers. A bug is already logged with Valve on this.
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