[BUG] Bulk Delete ImportDeleteRegistrations does not work

[Hilda-Sun]

Describe the bug

Unable to delete registrations from Notification Hub using ImportDeleteRegistrations.

Exception or Stack Trace

There are no exceptions or errors. The job completes successfully without any failures, and failed.txt is empty.

To Reproduce

Use the following code to submit an ImportDeleteRegistrations job:

NotificationHubClient client = NotificationHubClient.CreateClientFromConnectionString(nhConnection, hubName);
var job = await client.SubmitNotificationHubJobAsync(
new NotificationHubJob
{
JobType = NotificationHubJobType.ImportDeleteRegistrations,
OutputContainerUri = new Uri(outputContainerUri1),
ImportFileUri = new Uri(inputFileUri)
}
);

long i = 10;
while (i > 0 && job.Status != NotificationHubJobStatus.Completed)
{
job = await client.GetNotificationHubJobAsync(job.JobId);
await Task.Delay(1000);
i--;
}

Expected behavior
Registrations listed in the import file should be deleted after the job completes.

Screenshots
The job completes successfully without any errors. However, the registrations remain in the Notification Hub and can still be retrieved using the registration ID.

Setup (please complete the following information):

• OS: Win11
• IDE : Visual Studio 2022
• Version of the Library used: Microsoft.Azure.NotificationHubs 4.2.0