Decrypting Always Encrypted Column ASP.NET MVC App

Question

I've encrypted a couple of columns in a SQL database hosted in Azure. I did the encryption (deterministic) using AzureKeyVault. I've given the App Service in Azure itself access to the KeyVault. I've also added the Column Encryption Setting=enabled to the connection string. I'm using Entity Framework 6.0 for my data layer.

However when I run a query against a table that has the encryption, I simply receive a timeout error.

Execution Timeout Expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

I've looked at adding this code and calling it in my Global.asax Application_Start method:

public class AzureKeyValueConfiguration
{
    private static ClientCredential _clientCredential;

    public static void InitializeAzureKeyVaultProvider()
    {
        string clientId = "MyClient";
        string clientSecret = "MySecret";
        _clientCredential = new ClientCredential(clientId, clientSecret);

        SqlColumnEncryptionAzureKeyVaultProvider azureKeyVaultProvider = new SqlColumnEncryptionAzureKeyVaultProvider(GetToken);

        Dictionary<string, SqlColumnEncryptionKeyStoreProvider> providers =
            new Dictionary<string, SqlColumnEncryptionKeyStoreProvider>();

        providers.Add(SqlColumnEncryptionAzureKeyVaultProvider.ProviderName, azureKeyVaultProvider);
        SqlConnection.RegisterColumnEncryptionKeyStoreProviders(providers);
    }

    private async static Task<string> GetToken(string authority, string resource, string scope)
    {
        var authContext = new AuthenticationContext(authority);
        AuthenticationResult result = await authContext.AcquireTokenAsync(resource, _clientCredential);

        if (result == null)
            throw new InvalidOperationException("Failed to obtain the access token");

        return result.AccessToken;
    }
}

protected void Application_Start()
{
        FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
        RouteConfig.RegisterRoutes(RouteTable.Routes);
        AutoMapperConfiguration.Configure();
        log4net.Config.XmlConfigurator.Configure();
        AzureKeyValueConfiguration.InitializeAzureKeyVaultProvider();
}

However, I'm not even sure if this code is firing as I can't get it to hit in the debugger. All in all, I'm a bit lost and could use some guidance.

Thanks