Thanks for clear it up, Jacob.
Something I don't get: I never change the FS, it is always at 48 KHz in my studio. When I begin to work after a power cycle, the H9k shows 48 but the USB audio doesn't work until I change it. I have to change to 41, then again at 48 and then it works. If I don't do that it shows the FS mismatch. The digital part is clocked to AES input and it works perfectly without issues.
Sorry for the confusion with this. The H9000 is the USB clock source and determines the sample rate, but this information is not automatically communicated to the computer. That is why when you restart your equipment and everything is at the correct sample rate, you will still need to toggle the H9000 USB Audio sample rate to fix the USB audio mute. We may try and change this in the future, but toggling the H9000 USB Audio sample rate is the recommended solution for now.