Personal Flutter music player for iPhone: YouTube audio won’t play on my iPhone 8 ((-1) unknown error)

Hey everyone! I'm building a small music player in Flutter, just for me and my partner. It's meant for an iPhone 8 and an iPhone 17, but so far I've only tested it on the 8. I install it myself with Sideloadly, so it's strictly personal and will never be on the App Store.

The good news: the design, the search (YouTube Data API) and background audio all work. The bad news: I can't get any sound out of it.

Here's what I'm doing: youtube\_explode\_dart 3.1.0 grabs an audio-only MP4 stream (I've tried the ios and androidVr clients), I save it to the cache and play the file with just\_audio + just\_audio\_background. On the iPhone 8 (iOS 16) the player just shows "(-1) unknown error" and stays at 0:00.

I know YouTube doesn't allow this and that it can break at any time, but it's only for personal use, so I'm really just after the technical side. Has anyone got youtube\_explode\_dart playing on a real iPhone lately? Any ideas about clients, headers, or something else I might be missing?

Thanks a lot