ui: autocomplete: fix value() method

packages/ui-default/components/autocomplete/index.jsx

@@ -71,12 +71,8 @@ export default class AutoComplete extends DOMAttachedObject {
   }
 
   value() {
-    if (this.ref?.getSelectedItems) {
-      const selected = this.ref.getSelectedItems();
-      if (this.options.multi) return selected;
-      return selected[0];
-    }
-    return this.$dom.val();
+    if (this.options.multi) return this.$dom.val();
+    return this.ref?.getSelectedItems()[0] ?? null;
   }
 
   detach() {