Thank you for the update. Let's check Windows Privacy Settings next. Please go to Settings > Privacy > Microphone.
Make sure the toggle for "Allow apps to access your microphone" is turned on.
Scroll down and ensure that Xbox Game Bar has permission to access your microphone.
If issues still persist on above steps, I would suggest doing an SFC Scan next.
In the menu, select Command Prompt (Admin). NOTE: System File Checker can be run from Windows PowerShell (Admin). On the User Account Control (UAC) prompt, click Yes. In the command prompt window, type SFC /scannow and press Enter.
Please do let me know if issues still persist after the steps above.