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

@@ -101,10 +101,10 @@
     var data = e.params.data;
     formatCustomerSelection(data)
   })
 }
 
-document.addEventListener('DOMContentLoaded', function() {
+document.addEventListener("spree:load", function() {
   $('#customer_search').customerAutocomplete()
 
   if ($('#customer_autocomplete_template').length > 0) {
     window.customerTemplate = Handlebars.compile($('#customer_autocomplete_template').text())
   }