Series: Engineering gotchas
I put a batch of podcast audio files (.m4a) on Cloudflare R2 and embedded them with a plain <audio> tag. Desktop Chrome and Firefox played them perfectly. But on iPhone and iPad, they wouldn't play at all — tap the button, nothing happens, no error message, console completely clean.
The most maddening part: it throws no error. You have no idea where to even start looking.
This is how I tracked it down to the root cause, and the one-line fix at the end. If you googled "audio plays on desktop but not iphone" or "m4a not playing ios safari" and landed here, skip to section three.
First, rule out all the usual suspects
