Plugin Update from External Server Creates Different Slug Name

Hi

Am working on a plugin where the update will be done from external server. I used pre_set_site_transient_update_plugins filter,

add_filter('pre_set_site_transient_update_plugins', 'check_for_plugin_update');

I got this response as

array(1) {
  ["checked_data"]=>
  object(stdClass)#247 (4) {
    ["last_checked"]=>
    int(1458734817)
    ["response"]=>
    array(0) {
    }
    ["translations"]=>
    array(0) {
    }
    ["no_update"]=>
    array(0) {
    }
  }
}
array(1) {
  ["checked_data"]=>
  object(stdClass)#288 (5) {
    ["last_checked"]=>
    int(1458734817)
    ["checked"]=>
    array(1) {
      ["random-banner-pro/random-banner-pro.php"]=>
      string(5) "3.4.1"
    }
    ["response"]=>
    array(0) {
    }
    ["translations"]=>
    array(0) {
    }
    ["no_update"]=>
    array(0) {
    }
  }
}
Array
(
    [random-banner-pro/random-banner-pro.php] => stdClass Object
        (
            [name] => Random Banner
            [version] => 3.4.2
            [date] => 2016-03-22
            [author] => vinoth06
            [requires] => 4.2
            [tested] => 4.4
            [homepage] => https://ifecho.com
            [downloaded] => 10
            [external] =>
            [package] => https://ifecho.com/download/localhost/downloads/random-banner.zip
            [file_name] => random-banner.zip
            [sections] => Array
                (
                    [description] => Random Banner WordPress plugin provides users with high level of flexibility to show image banner and script ads randomly on Widgets
                    [change log] => Change log
                )

            [slug] => random-banner-pro
            [new_version] => 3.4.2
        )

)

But the folder name is changing from random-banner-pro to random-banner-Sx2FHT. Am not sure where I have did the mistake. Kindly suggest some solution

Note: I have used the below instruction
https://github.com/jeremyclark13/automatic-theme-plugin-update