google-cloud-dotnet: Exception while batch processing document with Google Cloud DocumentAI V1 - StatusCode="DeadlineExceeded"

I am trying to create PoC for Google Cloud DocumentAI V1 https://cloud.google.com/dotnet/docs/reference/Google.Cloud.DocumentAI.V1/latest

I am using DocAI to convert .pdf files into text using DocAI BatchProcessing. I have created console application with below code, which is working fine with single document. But when I try to process multiple pdf documents it’s throwing exception.

Application Code:

public static class DocAIBatchProcess
{
    const string projectId = "PROJECTID"; 
    const string processorId = "PROCESSID";
    const string location = "us";
    const string gcsInputBucketName = "BUCKETNAME";
    const string gcsOutputBucketName = "gs://BUCKETNAME/OUTPUTFOLDER/";
    const string gcsOutputUriPrefix = "PREFIX";
    const string prefix = "INPUTFOLDER/";
    const string delimiter = "/";

public static async Task<bool> BatchProcessDocumentAsync(this IEnumerable<GCPStorage.Object> storageObjects)
        {
            Console.WriteLine($"\n");
            Console.WriteLine($"Processing Start : {DateTime.UtcNow}");
            
            try
            {
                Console.WriteLine("\n");
                Console.WriteLine("Processing documents started...");
                Console.WriteLine("-------------------------------");

                // Create client
                DocumentProcessorServiceClient documentProcessorServiceClient = await DocumentProcessorServiceClient.CreateAsync();

                 GcsDocument gcsDocument = null;
                GcsDocuments gcsDocuments = new GcsDocuments();

                var storage = StorageClient.Create();
                foreach (var storageObject in storageObjects)
                {
                    if (storageObject.Name != prefix)
                    {
                        gcsDocument = new GcsDocument()
                        {
                            GcsUri = $"gs://cdx-dev/{storageObject.Name}",
                            MimeType = "application/pdf"
                        };
                        gcsDocuments.Documents.Add(gcsDocument);
                    }
                }

                BatchDocumentsInputConfig inputConfig = new BatchDocumentsInputConfig();
                inputConfig.GcsDocuments = gcsDocuments;

                //Output Config
                GcsOutputConfig gcsOutputConfig = new GcsOutputConfig();
                gcsOutputConfig.GcsUri = gcsOutputBucketName;

                DocumentOutputConfig documentOutputConfig = new DocumentOutputConfig();
                documentOutputConfig.GcsOutputConfig = gcsOutputConfig;

                // Initialize request argument(s)
                BatchProcessRequest request = new BatchProcessRequest
                {
                    ProcessorName = ProcessorName.FromProjectLocationProcessor(projectId, location, processorId),
                    SkipHumanReview = false,
                    InputDocuments = inputConfig,
                    DocumentOutputConfig = documentOutputConfig,
                };

                // Make the request
                Operation<BatchProcessResponse, BatchProcessMetadata> response = await documentProcessorServiceClient.BatchProcessDocumentsAsync(request);

                // Poll until the returned long-running operation is complete
                Operation<BatchProcessResponse, BatchProcessMetadata> completedResponse = await response.PollUntilCompletedAsync().ConfigureAwait(continueOnCapturedContext: false);

                // Retrieve the operation result
                BatchProcessResponse result = completedResponse.Result;

                // Or get the name of the operation
                string operationName = response.Name;
                
                // Check if the retrieved long-running operation has completed
                if (completedResponse.IsCompleted)
                {
                    // If it has completed, then access the result
                    BatchProcessResponse retrievedResult = completedResponse.Result;
                }
                Console.WriteLine($"Processing End : {DateTime.UtcNow}");
                Console.WriteLine("Processing documents completed...");
                return completedResponse.IsCompleted;
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
                Console.WriteLine($"Processing End : {DateTime.UtcNow}");
            }
            return false;
        }
}

DeadlineExceeded : “Deadline expired before operation could complete.”

I tried looking into documentation but couldn’t find anything. Is this issue with DocumentAI while processing in Batch ?