Laravel scheduler strange behavior in prod server

The scheduler is running at strange times, I have config a task to run every minute and locally runs OK, but in prod server runs like repeated at some times.

This is my Kernel.php code

namespace App\Console;

use Illuminate\Console\Scheduling\Schedule;
use Illuminate\Foundation\Console\Kernel as ConsoleKernel;

class Kernel extends ConsoleKernel
{

    protected $commands = [];


    protected function schedule(Schedule $schedule)
    {

        $schedule->call(function () {
            return true;
        })->everyMinute()->emailOutputTo('...')->thenPing('...');

    }

    protected function commands()
    {
        $this->load(__DIR__.'/Commands');

        require base_path('routes/console.php');
    }


}

The execution output I get from the prod server:

19.06
19.07
19.08
19.09
19.10
19.11
19.12
19.13
19.16
19.16
19.16
19.17
19.18
19.21
19.21
19.21
19.22
19.23
19.25
19.25
19.26

Any ideas?

via Chebli Mohamed