We have new HP Laptop with Realtek Audio running Windows 10 Home v20H2. It came with v2004 and HP updated trying to fix audio and missing microphone but this did not help. I have found the problem only happens when using Firefox. Viewing a video is not necessary to recreate the problem. What happens is the audio will stop playing when Firefox is open, even if only reading text on a webpage while listing to a music file with Groove Music. Whether or not a music player is running does not make a difference, even the beep sound when hitting the Number Lock key stops working. The other odd thing I did not notice right away is that the built-in Microphone device often disappears. Only used it once so far for Zoom and happened to notice it was missing from the Sound settings after the audio stopped. Restarting usually brings back the audio until Firefox is used again. Sometimes it works for 1 hr of a movie and stops. I found out that opening Groove and playing an mp3 usually gets the sound back but not the microphone. The first apps installed on the computer were Firefox, Thunderbird, Zoom and then Adobe CS 5.5 & 6 and now Retrospect Backup. The first occurrence of the sound stopping was when only FF and TB were installed but we thought it was the website. Using Edge (which we don't prefer) the audio always works fine. HP replaced the Realtek Audio drivers which did not fix the problem but lost the equalizer function and some of the bit depth and enhancement choices in the speaker settings. I have attached screen shots of the Sound, Video and Game controller Realtek Audio properties and Audio Input and output Speaker driver properties from the device manager. Note, I am not posting this from the problem computer because Firefox account kept rejecting my password even though the correct password was pasted in. I tried it in Internet explorer on this win7 computer and that would not work either. Not sure why I can't sign in on another computer when I am logged out of my Firefox account on this computer.