Microsoft Support:
AC-3 is an audio codec that supports multi-channel (“surround sound”) audio. It’s also known as Dolby Digital.
On versions of Windows prior to Windows 11, version 24H2, the AC-3 codec is included.
This is not so much a problem with Plex, but a mess of communication in the industry when it comes to evolving codecs. I believe I have found a solution to the issue which was posted. Took me a day to find it scouring the web,
The problem
Beginning with Windows 11, version 24H2, the AC-3 codec is no longer included with Windows. However, many device manufacturers will pre-install an AC-3 codec. Also, if you upgrade to Windows 11, version 24H2 from an earlier version of Windows, the AC-3 codec will be retained. In these cases, you will still be able to play files encoded with the AC-3 audio codec.
The solution
Microsoft Dolby Digital Atmos Pack version 10.0.22621.4317
- Microsoft Dolby Digital Atmos Pack standalone installer.
Link to this wonderful individuals work.
Release AnWave 2024 Split Feature Release · SimonMacer/AnWave · GitHub
Link to download the driver install.
Microsoft.Dolby.Digital.Atmos.Pack-v10.0.22621.4317-20241013.zip
I hope this makes everyone happy, it did me. There is some other cool things there if you explore.