After starting something that plays audio, could you check the Windows Volume Mixer. To open that, right-click the speaker icon in the notification area of the Taskbar. This should show whether Firefox is muted, and if you click the little v icon on the right, whether it is sending output to a disconnected device. <blockquote><img src="https://assets-prod.sumo.prod.webservices.mozgcp.net/media/uploads/images/2025-09-14-17-11-35-eb82c4.png"></blockquote> ''Note: that is Windows 11, and I can't remember how it differs from Windows 10.''