is_active_sidebar() problem

I'm trying to develop a wordpress theme with a hero slider, I use some 3rd party slider widget inserted to the hero widget area I've defined as sidebar-hero in my functions.php file.

I'm using this code to display the hero slider:

?php if(is_active_sidebar("sidebar-hero")) : ?
    ?php dynamic_sidebar("sidebar-hero");?
    script type="text/javascript"document.body.classList.add("hero-widget-enabled");/script
?php else: ?
div class="carousel-page-container container"
    div class="header-filter" style='background-image: url(/wp-content/themes/sometheme/assets/images/demo/back.png)'
        div class="header-filter-gradient"/div
        /div
    /div
/div
?php endif;?

Now the problem is, I add the custom slider to the sidebar-hero widget area, it shows the slider. I remove the slider from the widgets, it shows the default image. But when I disable the slider from the extensions page without removing it from the widget area, it still tries to show the dynamic sidebar.

The is_active_sidebar() method returns true even if there are any widgets displayed in the widget settings page on the sidebar-hero widget area.

Do you have any solutions for this issue? Is it a wordpress bug, or am I doing something wrong?

Update

wp_get_sidebars_widgets() shows this output (which smartslider3-2 should not be included because it's plugin is disabled):

array(6) {
  ["wp_inactive_widgets"]=
  array(11) {
    [0]=
    string(10) "archives-2"
    [1]=
    string(10) "archives-4"
    [2]=
    string(6) "meta-2"
    [3]=
    string(8) "search-2"
    [4]=
    string(8) "search-4"
    [5]=
    string(6) "text-2"
    [6]=
    string(12) "categories-2"
    [7]=
    string(14) "recent-posts-2"
    [8]=
    string(17) "recent-comments-2"
    [9]=
    string(6) "text-3"
    [10]=
    string(11) "tag_cloud-2"
  }
  ["sidebar-primary"]=
  array(3) {
    [0]=
    string(12) "categories-3"
    [1]=
    string(11) "tag_cloud-1"
    [2]=
    string(10) "calendar-1"
  }
  ["sidebar-footer-1"]=
  array(1) {
    [0]=
    string(14) "recent-posts-3"
  }
  ["sidebar-footer-2"]=
  array(1) {
    [0]=
    string(7) "pages-2"
  }
  ["sidebar-footer-3"]=
  array(1) {
    [0]=
    string(11) "tag_cloud-3"
  }
  ["sidebar-hero"]=
  array(1) {
    [0]=
    string(14) "smartslider3-2"
  }
}