diff --git a/CHANGELOG.md b/CHANGELOG.md
index 38880eecd3..be8807fd8d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
 
 ### Client
 - Feat: MFMを考慮してテキストを操作するAiScript関数を追加
+- Fix: 画面サイズが変わった際にナビゲーションバーが自動で折りたたまれない問題を修正
 
 ### Server
 -
diff --git a/packages/frontend/src/ui/_common_/navbar.vue b/packages/frontend/src/ui/_common_/navbar.vue
index 8fc76741e3..9724905e02 100644
--- a/packages/frontend/src/ui/_common_/navbar.vue
+++ b/packages/frontend/src/ui/_common_/navbar.vue
@@ -36,7 +36,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 				</component>
 			</template>
 			<div :class="$style.divider"></div>
-			<MkA v-if="$i.isAdmin || $i.isModerator" v-tooltip.noDelay.right="i18n.ts.controlPanel" :class="$style.item" :activeClass="$style.active" to="/admin">
+			<MkA v-if="$i != null && ($i.isAdmin || $i.isModerator)" v-tooltip.noDelay.right="i18n.ts.controlPanel" :class="$style.item" :activeClass="$style.active" to="/admin">
 				<i :class="$style.itemIcon" class="ti ti-dashboard ti-fw"></i><span :class="$style.itemText">{{ i18n.ts.controlPanel }}</span>
 			</MkA>
 			<button class="_button" :class="$style.item" @click="more">
@@ -48,10 +48,10 @@ SPDX-License-Identifier: AGPL-3.0-only
 			</MkA>
 		</div>
 		<div :class="$style.bottom">
-			<button v-tooltip.noDelay.right="i18n.ts.note" class="_button" :class="[$style.post]" data-cy-open-post-form @click="os.post">
+			<button v-tooltip.noDelay.right="i18n.ts.note" class="_button" :class="[$style.post]" data-cy-open-post-form @click="() => { os.post(); }">
 				<i class="ti ti-pencil ti-fw" :class="$style.postIcon"></i><span :class="$style.postText">{{ i18n.ts.note }}</span>
 			</button>
-			<button v-tooltip.noDelay.right="`${i18n.ts.account}: @${$i.username}`" class="_button" :class="[$style.account]" @click="openAccountMenu">
+			<button v-if="$i != null" v-tooltip.noDelay.right="`${i18n.ts.account}: @${$i.username}`" class="_button" :class="[$style.account]" @click="openAccountMenu">
 				<MkAvatar :user="$i" :class="$style.avatar"/><MkAcct class="_nowrap" :class="$style.acct" :user="$i"/>
 			</button>
 		</div>
@@ -83,8 +83,12 @@ import { $i, openAccountMenu as openAccountMenu_ } from '@/account.js';
 import { defaultStore } from '@/store.js';
 import { i18n } from '@/i18n.js';
 import { instance } from '@/instance.js';
+import { getHTMLElementOrNull } from '@/scripts/get-dom-node-or-null.js';
 
-const iconOnly = ref(false);
+const forceIconOnly = ref(window.innerWidth <= 1279);
+const iconOnly = computed(() => {
+	return forceIconOnly.value || (defaultStore.reactiveState.menuDisplay.value === 'sideIcon');
+});
 
 const menu = computed(() => defaultStore.state.menu);
 const otherMenuItemIndicated = computed(() => {
@@ -95,14 +99,10 @@ const otherMenuItemIndicated = computed(() => {
 	return false;
 });
 
-const forceIconOnly = window.innerWidth <= 1279;
-
 function calcViewState() {
-	iconOnly.value = forceIconOnly || (defaultStore.state.menuDisplay === 'sideIcon');
+	forceIconOnly.value = window.innerWidth <= 1279;
 }
 
-calcViewState();
-
 window.addEventListener('resize', calcViewState);
 
 watch(defaultStore.reactiveState.menuDisplay, () => {
@@ -120,8 +120,10 @@ function openAccountMenu(ev: MouseEvent) {
 }
 
 function more(ev: MouseEvent) {
+	const target = getHTMLElementOrNull(ev.currentTarget ?? ev.target);
+	if (!target) return;
 	const { dispose } = os.popup(defineAsyncComponent(() => import('@/components/MkLaunchPad.vue')), {
-		src: ev.currentTarget ?? ev.target,
+		src: target,
 	}, {
 		closed: () => dispose(),
 	});