Cloudfront Access Denied, but only on certain files

I've read through several similar issues, but they differ in that

1. This isn't a website, just CDN for images
2. I have no subdirectories

I was notified by our marketing dept that some of our photos weren't serving. I went to the actual CloudFront URL and I get a 403 Forbidden. Typically this means the Everyone permission is wrong, so I went to the AWS console and checked the S3 bucket. The image had a proper Everyone - Read permission. Just for kicks, I removed the permission and re-added. Still 403. I expired it out of CloudFront thinking maybe cache was the issue. Still 403.

Other images in the same bucket are served just fine (so it doesn't seem to be bucket permissions), and it's just a handful of old ones doing this. I'm to the point of removing and re-adding them just to see if that fixes it, but I was wondering if there was some other way to diagnose or fix the issue.