No Dolby ac3 sound - iTunes for Windows

When trying to play mp4 TV shows or movies using iTunes for Windows on Windows 11 (23H2), .ac3 (Dolby) audio won't play. If the video also contains an AAC audio track, that plays. And AAC or ALAC audio play in the music part of my library. I've tried switching Playback back and forth between DirectShow and the alternative. I've tried different sampling rates and bit depths.

I've also tried a complete uninstallation and reinstallation of iTunes 12. I began with 12.13, I believe that what I just reinstalled is 12.11, downloaded from Apple.

The audio for the videos in question plays fine in VLC, Windows Media Player Classic, Windows Movies and TV, etc. But no sound from speakers or headphones using iTunes. The same files play audio fine in iTunes, Movies or QuickTime Player on both new and old Macs. So I'm running out of ideas at the moment.