Why was this happening? Apple stopped officially supporting the 2012 MacBook Pro for Windows 10 after the 2015 Boot Camp update. The newer Cirrus drivers assumed a different hardware revision or power management scheme. But the older driver—built for Windows 8.1—happened to use a compatible HDA verb table that the Windows 10 audio stack still understood. The generic Microsoft driver lacked those specific initialization commands.
rather than EFI boot to expose the Cirrus Logic audio hardware. If you have a red "X" on your speaker icon, follow this guide to resolve it. Apple Support Community 1. Identify Your Boot Mode
If it says , your audio likely won't work regardless of the driver you install. You may need to reinstall Windows 10 using a standard MBR/Legacy boot method rather than the EFI boot option. 2. Install the Right Driver Package