Ticket #30223: 30223.diff

src/wp-includes/js/customize-base.js

@@ -430 +430 @@
                                                 synchronizer = api.Element.synchronizer[ type ];
                                         if ( 'text' === type || 'password' === type )
                                                 this.events += ' keyup';
+                                        else if ( 'range' === type )
+                                                this.events += ' input propertychange';
                                 } else if ( this.element.is('textarea') ) {
                                         this.events += ' keyup';
                                 }