app/assets/javascripts/spree/backend/promotions.js in spree_backend-4.3.3 vs app/assets/javascripts/spree/backend/promotions.js in spree_backend-4.4.0.rc1

@@ -14,14 +14,16 @@
     $typeSelect.change(function () {
       if ($(this).val() === originalType) {
         $warning.hide()
         $settings.show()
         $settings.find('input').removeProp('disabled')
+        $settings.find('select').removeProp('disabled')
       } else {
         $warning.show()
         $settings.hide()
         $settings.find('input').prop('disabled', 'disabled')
+        $settings.find('select').prop('disabled', 'disabled')
       }
     })
   })
 
   //
@@ -159,10 +161,10 @@
       return false
     })
   })()
 }
 
-$(document).ready(function () {
+document.addEventListener("spree:load", function() {
   var promotion_form = $('form.edit_promotion')
 
   if (promotion_form.length) {
     initProductActions()
   }