Sometime execute scheduled job twice,

bug?
1

A scheduled background job is to execute twice. Not sure why this is happening.

Schedule Job Code
-> var res = BackgroundJob.Enqueue(() => PickingUser(liRequestId));

Configuration

public void Configuration(IAppBuilder loIAppBuilder)
    {
		loIAppBuilder.UseHangfireAspNet(GetHangfireServers);
		loIAppBuilder.UseHangfireDashboard();
		HttpConfiguration loHttpConfiguration = new HttpConfiguration();
        loHttpConfiguration.IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always;

        ConfigureAuth(loIAppBuilder);

        WebApiConfig.Register(loHttpConfiguration);
        loIAppBuilder.UseWebApi(loHttpConfiguration);
    }

private IEnumerable GetHangfireServers()
{
string lsConnectionString = string.Empty;
lsConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings[“userContDB”].ConnectionString;
Hangfire.GlobalConfiguration.Configuration
.SetDataCompatibilityLevel(CompatibilityLevel.Version_170)
.UseSimpleAssemblyNameTypeSerializer()
.UseRecommendedSerializerSettings()
.UseSqlServerStorage(lsConnectionString, new SqlServerStorageOptions
{
CommandBatchMaxTimeout = TimeSpan.FromMinutes(5),
SlidingInvisibilityTimeout = TimeSpan.FromMinutes(5),
QueuePollInterval = TimeSpan.Zero,
UseRecommendedIsolationLevel = true,
UsePageLocksOnDequeue = true,
DisableGlobalLocks = true
});
GlobalJobFilters.Filters.Add(new AutomaticRetryAttribute { Attempts = 1 });
yield return new BackgroundJobServer();
}

Some time it will start execution twice and update details twice.