Azure CloudBlobContainer.CreateIfNotExists() throws the container already exists error with crashes webpage

Question

I have a asp.net core app that uploads file to azure blob storage. The upload completes successfully but when CloudBlobContainer calls CreateIfNotExistAsync the web page crashes with a "The container already exists error".

  var container = BlobClient.GetContainerReference(containerName.ToString().ToLower());

 await container.CreateIfNotExistsAsync();
 return container;

I have tried using surronding CreateIfNotExistsAsync() with the following if

if (! await container.ExistsAsync())

but that still errors.

The container name and the AccountName= in the connection string is lowercase.

I am using the latest stable Microsoft.Azure.Storage.Blob NuGet package 10.0.2

I have tried to catch the StroageExeception but the exception is not called

 try
    {
       await container.CreateIfNotExistsAsync();
    }
    catch (StorageException ex)
    {
        Logger.LogError(ex.ToString());
    }

I have been through all the points in this previous question but none of them apply/work in my scenario Azure Blob 400 Bad request on Creation of container

public class CloudBlobStorageProvider : ICloudBlobStorageProvider
{
    private CloudBlobClient BlobClient { get; }
    private ILogger Logger { get; }

    public CloudBlobStorageProvider(IConfiguration configuration, ILogger<CloudBlobStorageProvider> logger)
    {
        var connectionString = configuration.GetConnectionString("AzureStorageAccount");

        if (!CloudStorageAccount.TryParse(connectionString, out CloudStorageAccount storageAccount))
        {
            logger.LogError($"The supplied connection string for Azure blob storage could not be parsed: {connectionString}");
        }

        BlobClient = storageAccount.CreateCloudBlobClient();
    }

    public async Task<CloudBlobContainer> GetContainerAsync(CloudBlobContainerName containerName)
    {

        var container = BlobClient.GetContainerReference(containerName.ToString().ToLower());

        await container.CreateIfNotExistsAsync(BlobContainerPublicAccessType.Off, null, null);

        return container;
    }
}

public interface ICloudBlobStorageProvider
{
    Task<CloudBlobContainer> GetContainerAsync(CloudBlobContainerName containerName);
}

Which is called by

 public async Task<CloudBlockBlob> UploadServiceUserAttachmentAsync(IFormFile formFile)
    {
        var fileExtenion = RegularExpressionHelpers.GetFileExtension(formFile.FileName);

        string attachmentFileName = (string.IsNullOrEmpty(fileExtenion)) ? $"{Guid.NewGuid().ToString()}" : $"{Guid.NewGuid().ToString()}{fileExtenion}";

        var userAttachmentContainer = await CloudBlobStorageProvider.GetContainerAsync(CloudBlobContainerName.userattachments);

        var blobBlockReference = userAttachmentContainer.GetBlockBlobReference(attachmentFileName);

        try
        {
            using (var stream = formFile.OpenReadStream())
            {
                await blobBlockReference.UploadFromStreamAsync(stream);
                await blobBlockReference.FetchAttributesAsync();
                var blobProperties = blobBlockReference.Properties;
                blobProperties.ContentType = formFile.ContentType;
                await blobBlockReference.SetPropertiesAsync();
            }
        }
        catch (Exception e)
        {
            Logger.LogWarning(e, $"Exception encountered while attempting to write profile photo to blob storage");

        }

        return blobBlockReference;
    }