An error occurred during export on ProRes log iPhone footage

I recently purchased an iPhone 16 Pro and have been filming in ProRes Log. When I import my log footage into iMovie on my iPhone (or on my 3rd generation iPad Pro also running iOS 18) and go to export my movie, I’m instantly met with the message ‘An error occurred during export.’ It doesn’t matter if the footage is HD or 4k or if it is raw footage or if I’ve made adjustments inside Photos. From what I’ve read, it seems like iMovie on iOS should be able to handle ProRes log footage. Is anyone else having this issue?