Change binding type

src/Umbraco.Web.UI.Client/src/common/directives/components/buttons/umbbutton.directive.js

@@ -99,7 +99,7 @@ Use this directive to render an umbraco button. The directive can be used to gen
                 alias: "@?",
                 addEllipsis: "@?",
                 showCaret: "@?",
-                autoFocus: "@?",
+                autoFocus: "<?",
                 hasPopup: "@?",
                 isExpanded: "<?"
             }