Ajax loader when facet is selected
You can try the following.

Add in your JS file:

$(document).ajaxStart(function(){
  $('#ajax_loading').show();
});

$(document).ajaxStop(function() {
  $('#ajax_loading').hide();
});


Add the HTML in your page:

&lt;div id="ajax_loading" style="display:none"&gt;


Add in your CSS file:

#ajax_loading {
  position: fixed;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  background: rgba(0,0,0,0.5);
  z-index: 9999;
}