A USB speaker in preview mode is suddenly recognized as a Steam Streaming device

The update appears to have changed device association or driver selection, causing the USB speaker to be exposed through Steam’s virtual streaming-audio path instead of its normal hardware endpoint. First open Sound settings, select the physical USB speaker as the default output device, and confirm its test tone works. Fully exit Steam, disable Remote Play temporarily, and check whether the physical endpoint returns. In Device Manager, show hidden devices, remove only the affected speaker and Steam Streaming audio entries, then restart so Windows can enumerate the USB device again. Install the speaker or motherboard USB/audio driver from the manufacturer. If this began immediately after an Insider build, return to the previous build while the rollback window remains open. Otherwise submit the device IDs, build number, and reproduction steps through Feedback Hub. Do not delete unrelated audio codecs or registry device classes.