No sound on certain downloaded movies after updating to iPadOS 18.6

Immediately after updating to iOS 18.6 three of the downloaded movies on my iPad have no sound. Others have sound and all other sound functionality seems okay but I can find no way to restore the sound on the three movies. I have shut down and restarted the device. I have restored original settings.

[Re-Titled by Moderator]

Original Title: No sound on certain downloaded movies after iO