According to Blackmagic Design, AC-3 support for DaVinci Studio comes from the operating system. The application works under Windows 10 but not under Windows 11.
I installed K-Lite but all it does is provide a new Media Player (that does play AC-3 audio files). The old Microsoft Media Player is still available in the Windows 11 operating system but still does not play AC-3 audio tracks.
So unless the Operating system can have the AC-3 codecs installed, these two applications are not functional with any modern video or audio file that has AC-3 audio.
So, I am back to the original question: where are the system AC-3 audio codecs to be found? Where does Microsoft have them for download?