Had this issue on a Win 11 HP laptop. Issue started after a Win 11 update. Mic had worked before the Win 11 update.
What worked for me was first turning OFF Audio Enhancements in the settings (Settings > System > Sound > All sound devices > select the device (mic) and turn OFF “Audio Enhancements).
Specifically on my HP laptop (and with Zoom), mine also had HP B&O app (Bang and Olufsen) installed on it that also influences microphone settings. I also had to turn off all microphone mic input enhancements to get my mic to work again specifically in Zoom. (Found this fix specifically for HP laptops on a Zoom forum).
Hope this helps.