I have a Lenovo ThinkPad X1 Yoga Gen 6 (20XY005MGE) with Win11 Pro. All of a sudden, Firefox does not play any sound. I notice that it does not show up in the volume mixer. I tried: * this solution: https://support.mozilla.org/de/questions/1278299 * Reboot the PC * Uninstall and reinstall Firefox * Deactivate all Extensions * I worked my way through the manual pages (none of which mentions Firefox missing in the volume mixer) Youtube does not play sounds, the Spotify page notices that it cannot play sound (the spotify App for Windows works fine, though). News sites (tagesschau.de / video, deutschlandfunk.de / audio) play the video, but no sound. I had the problem a few months ago already but I cannot recall the solution :( Thanks for helpful hints!