Select2 not working inside bootstrap modal

place this somewhere in your JS:

   //fix modal force focus
   $.fn.modal.Constructor.prototype.enforceFocus = function () {
      var that = this;
      $(document).on('focusin.modal', function (e) {
         if ($(e.target).hasClass('select2-input')) {
            return true;
         }

         if (that.$element[0] !== e.target && !that.$element.has(e.target).length) {
            that.$element.focus();
         }
      });
   };

Use bellow code. This will solve your bug.

$('select').select2({
    dropdownParent: $('#my_amazing_modal')
});