Did you verify that Win11 wasn't blocking the Mic options? You might want to start there first since the O/S controls those features. I seen where in Win10 you can block the Mic/webcam but won't notice it til you go and check those settings and test them there.

After you check your Windows Settings -

How to manage your camera and microphone permissions with Firefox https://support.mozilla.org/en-US/kb/how-manage-your-camera-and-microphone-permissions

Also, there are test sites like Online MicTest where you can ensure things are working properly.

See e.g.:

• https://www.onlinemictest.com/