Use correct store declaration

store/index.js

+import Vuex from 'vuex'
+
 import actions from './actions'
 import mutations from './mutations'
 import getters from './getters'
 
-export default {
-  state() {
-    return {
+export default () => {
+  return new Vuex.Store({
+    state: {
       activeType: null,
       itemsPerPage: 20,
       items: {/* [id: number]: Item */},
@@ -16,9 +18,9 @@ export default {
         ask: [],
         job: []
       }
-    }
     },
     actions,
     mutations,
     getters
+  })
 }