Interface.exe have a big hugh long standing bug and i think the devs did know that for a long time. Since a few weeks ago i know why i always did have audio problems.
See this thread on how to disable in steamVR the functionalit.
The big problem and bug is that interface.exe is ignoring that setting complete. and making a choas on your system. Especially with your sound settings. Normally you set steamVR so it use your HMD sound card and microphone. But you not want that in desktop mode. But as soon interface is starting, its strating against what the user did config steamVR.
Screwed audio playback device etc. !
And a new problem, because steamVR is not running so you start it. But steamVR cannot update because high fidlity hijacked steamVR and never closed it when you close interfece.exe besides it’s aleready a bug that it’s starting steamVR.
Anyway, if you did run high fidelity before you did run steamVR. because you where in hifi desktop mode. And then start steamVR, it cannot update.
This error is fully to blame at high fidelity and interface that did run steamVR.
DO NOT START SteamVR at boot.
Just check if steamVR is running, if not disable the HMD parts in interface.exe. Thats the correct implementation. Not run steam against users will and then let the user figure out how to end the tasks (VR Compositor and VR dashboard need to be killed manual) You also need to kill them manual after every use of interface.
And because this bug you not use VR voice anymore because steamVR need to be set to the correct playback device. But that makes you lose audio in VR.