fix(client): Fix #6540

src/client/init.ts

@@ -103,9 +103,13 @@ document.body.innerHTML = '<div id="app"></div>';
 
 const store = createStore();
 
+// 他のタブと永続化されたstateを同期
 window.addEventListener('storage', e => {
 	if (e.key === 'vuex') {
-		store.replaceState(JSON.parse(localStorage['vuex']));
+		store.replaceState({
+			...store.state,
+			...JSON.parse(e.newValue)
+		});
 	} else if (e.key === 'i') {
 		location.reload();
 	}