I recieve this error and was told in a microsoft support chat to post the question on here:
Import operation for PoC_backup_2021_09_07_230001_9912085 failed.
ErrorMessage: The ImportExport operation with Request Id 'cef8c17a-4c3d-4a32-afdf-aaf4d1018f67' failed due to 'The package file provided was not able to be opened. Please run SqlPackage locally to ensure that the file is not corrupt and please ensure that it uploaded to Azure Storage completely.'.