Bootcamp Windows 10 internal speakers don't work, audio port lights red
I finally found a way to solve this issue:
First in OSX, I installed the &quot;Latest Windows support software from Apple&quot; on a USB flash drive via Utilities -&gt; Boot Camp Assistant.
Then in Windows, I reinstalled the missing audio driver using the BootCamp.msi installation file located in WindowsSupport/BootCamp/Drivers/Apple in said USB flash drive.
Internal speakers now work normally again, and the audio port no longer lights red!