I found the solution myself. The problem was that Laravel was unaware whether the request was secure or not because nginx didn't pass the HTTPS parameter.

For those who wonder, you can add it with this line in the nginx config:

fastcgi_param  HTTPS on;

In that case the first example works. The second example worked partly because of the poor implementation of in_array(). The next function, located in Illuminate/Routing/Route.php returns true even if a key name of the array is "https".

public function httpOnly()
{
        return in_array('http', $this->action);
}

A better function would be to add true to make it strict and more correct.

public function httpOnly()
{
        return in_array('http', $this->action, true);
}