Cached audio files fail to stream

I’m a Pro Plan customer that uses the Cloudflare Origin CA certificate to provide SSL for my site. I’d like to host audio files on my site, referenced with the HTML5 audio tag. Files hosted this way doesn’t always work, sometimes they stop streaming mid file.

I’m not sure why that happens but I seems like it’s a result of the CF Proxy/caching. It’s much more reliable when I don’t use the cache. Using the Cloudflare Origin CA means that turning off the cache turns off the SSL. That’s unacceptable.

I created a subdomain for my audio files, then created a Page Rule:* Cache Level: Bypass - but that doesn’t seem to work.

I’m considering buying an SSL certificate so I have have uncached HTTPS.

Has anyone else had this experience?