diff --git a/CHANGELOG.md b/CHANGELOG.md
index 46ec50f779..c316ebebe3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -31,6 +31,8 @@
   [ghsa-gq5q-c77c-v236](https://github.com/misskey-dev/misskey/security/advisories/ghsa-gq5q-c77c-v236)
 - Fix: 招待コードの発行可能な残り数算出に使用すべきロールポリシーの値が違う問題を修正  
   (Cherry-picked from https://activitypub.software/TransFem-org/Sharkey/-/merge_requests/706)
+- Fix: 連合への配信時に、acctの大小文字が区別されてしまい正しくメンションが処理されないことがある問題を修正  
+  (Cherry-picked from https://activitypub.software/TransFem-org/Sharkey/-/merge_requests/711)
 - Fix: FTT無効時にユーザーリストタイムラインが使用できない問題を修正  
   (Cherry-picked from https://activitypub.software/TransFem-org/Sharkey/-/merge_requests/709)
 
diff --git a/packages/backend/src/core/MfmService.ts b/packages/backend/src/core/MfmService.ts
index d33b228c3d..edfb3aa4fc 100644
--- a/packages/backend/src/core/MfmService.ts
+++ b/packages/backend/src/core/MfmService.ts
@@ -406,7 +406,7 @@ export class MfmService {
 			mention: (node) => {
 				const a = doc.createElement('a');
 				const { username, host, acct } = node.props;
-				const remoteUserInfo = mentionedRemoteUsers.find(remoteUser => remoteUser.username === username && remoteUser.host === host);
+				const remoteUserInfo = mentionedRemoteUsers.find(remoteUser => remoteUser.username.toLowerCase() === username.toLowerCase() && remoteUser.host?.toLowerCase() === host?.toLowerCase());
 				a.setAttribute('href', remoteUserInfo ? (remoteUserInfo.url ? remoteUserInfo.url : remoteUserInfo.uri) : `${this.config.url}/${acct}`);
 				a.className = 'u-url mention';
 				a.textContent = acct;
diff --git a/packages/frontend/src/components/MkNote.vue b/packages/frontend/src/components/MkNote.vue
index 3de69d6d09..cf0d0787b1 100644
--- a/packages/frontend/src/components/MkNote.vue
+++ b/packages/frontend/src/components/MkNote.vue
@@ -292,15 +292,18 @@ function checkMute(noteToCheck: Misskey.entities.Note, mutedWords: Array<string
 function checkMute(noteToCheck: Misskey.entities.Note, mutedWords: Array<string | string[]> | undefined | null, checkOnly: false): boolean | 'sensitiveMute';
 */
 function checkMute(noteToCheck: Misskey.entities.Note, mutedWords: Array<string | string[]> | undefined | null, checkOnly = false): boolean | 'sensitiveMute' {
-	if (mutedWords == null) return false;
-
-	if (checkWordMute(noteToCheck, $i, mutedWords)) return true;
-	if (noteToCheck.reply && checkWordMute(noteToCheck.reply, $i, mutedWords)) return true;
-	if (noteToCheck.renote && checkWordMute(noteToCheck.renote, $i, mutedWords)) return true;
+	if (mutedWords != null) {
+		if (checkWordMute(noteToCheck, $i, mutedWords)) return true;
+		if (noteToCheck.reply && checkWordMute(noteToCheck.reply, $i, mutedWords)) return true;
+		if (noteToCheck.renote && checkWordMute(noteToCheck.renote, $i, mutedWords)) return true;
+	}
 
 	if (checkOnly) return false;
 
-	if (inTimeline && !tl_withSensitive.value && noteToCheck.files?.some((v) => v.isSensitive)) return 'sensitiveMute';
+	if (inTimeline && tl_withSensitive.value === false && noteToCheck.files?.some((v) => v.isSensitive)) {
+		return 'sensitiveMute';
+	}
+
 	return false;
 }
 
diff --git a/packages/frontend/src/components/MkTimeline.vue b/packages/frontend/src/components/MkTimeline.vue
index 226faac291..fb8eb4ae37 100644
--- a/packages/frontend/src/components/MkTimeline.vue
+++ b/packages/frontend/src/components/MkTimeline.vue
@@ -43,6 +43,7 @@ const props = withDefaults(defineProps<{
 }>(), {
 	withRenotes: true,
 	withReplies: false,
+	withSensitive: true,
 	onlyFiles: false,
 });
 
diff --git a/packages/frontend/src/pages/timeline.vue b/packages/frontend/src/pages/timeline.vue
index 7a3195304b..044a1908ab 100644
--- a/packages/frontend/src/pages/timeline.vue
+++ b/packages/frontend/src/pages/timeline.vue
@@ -17,7 +17,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 				<div :class="$style.tl">
 					<MkTimeline
 						ref="tlComponent"
-						:key="src + withRenotes + withReplies + onlyFiles"
+						:key="src + withRenotes + withReplies + onlyFiles + withSensitive"
 						:src="src.split(':')[0]"
 						:list="src.split(':')[1]"
 						:withRenotes="withRenotes"