Happened again in iOS 15 beta 1. FB9179349

Same. But only happens to some videos. Also happening in macOS in all system players (Safari, Quicktime). But works in Chrome on Mac.

Hi, it's probably a code signing issue. With iOS 15 a new code signing format is enforced. Learn more here: https://developer.apple.com/documentation/xcode/using-the-latest-code-signature-format