While testing and importing files from the Broker make sure that file size is less than 1 MB. With the broker we cannot process files that are larger than 1 MB because it basically stops customers from controlling what files we can access - we would be able to access every file if we wanted through the big files API.
To address this issue, an additional Blob API endpoint should be whitelisted in
accept.json. This should be in a private array
"//": "used to get given manifest file",
Reference: Broker troubleshooting