diff --git a/addons/mail/static/src/core/web/message_patch.js b/addons/mail/static/src/core/web/message_patch.js
index 64ec5f961af..ee6f82e8925 100644
--- a/addons/mail/static/src/core/web/message_patch.js
+++ b/addons/mail/static/src/core/web/message_patch.js
@@ -35,16 +35,7 @@ patch(Message.prototype, "mail/core/web", {
         }
     },
     openRecord() {
-        if (this.message.resModel === "discuss.channel") {
-            this.threadService.open(this.message.originThread);
-        } else {
-            this.action.doAction({
-                type: "ir.actions.act_window",
-                res_id: this.message.resId,
-                res_model: this.message.resModel,
-                views: [[false, "form"]],
-            });
-        }
+        this.threadService.open(this.message.originThread);
     },
 
     /**
diff --git a/addons/mail/static/src/core/web/thread_service_patch.js b/addons/mail/static/src/core/web/thread_service_patch.js
index 8fe98c05b64..0f6a2e5f6ba 100644
--- a/addons/mail/static/src/core/web/thread_service_patch.js
+++ b/addons/mail/static/src/core/web/thread_service_patch.js
@@ -15,6 +15,7 @@ let nextId = 1;
 patch(ThreadService.prototype, "mail/core/web", {
     setup(env, services) {
         this._super(env, services);
+        this.action = services.action;
         /** @type {import("@mail/core/common/attachment_service").AttachmentService} */
         this.attachmentService = services["mail.attachment"];
         /** @type {import("@mail/core/web/activity_service").ActivityService} */
@@ -199,8 +200,22 @@ patch(ThreadService.prototype, "mail/core/web", {
         }
     },
     open(thread, replaceNewMessageChatWindow) {
-        if (!this.store.discuss.isActive || this.ui.isSmall) {
-            this.chatWindowService.open(thread, replaceNewMessageChatWindow);
+        if (!this.store.discuss.isActive && !this.ui.isSmall) {
+            this._openChatWindow(thread, replaceNewMessageChatWindow);
+            return;
+        }
+        if (this.ui.isSmall && thread.model === "discuss.channel") {
+            this._openChatWindow(thread, replaceNewMessageChatWindow);
+            return;
+        }
+        if (thread.model !== "discuss.channel") {
+            this.action.doAction({
+                type: "ir.actions.act_window",
+                res_id: thread.id,
+                res_model: thread.model,
+                views: [[false, "form"]],
+            });
+            return;
         }
         this._super(thread, replaceNewMessageChatWindow);
     },
@@ -227,11 +242,24 @@ patch(ThreadService.prototype, "mail/core/web", {
         }
         this._super(...arguments);
     },
+    _openChatWindow(thread, replaceNewMessageChatWindow) {
+        const chatWindow = this.chatWindowService.insert({
+            folded: false,
+            thread,
+            replaceNewMessageChatWindow,
+        });
+        chatWindow.autofocus++;
+        if (thread) {
+            thread.state = "open";
+        }
+        this.chatWindowService.notifyState(chatWindow);
+    },
 });
 
 patch(threadService, "mail/core/web", {
     dependencies: [
         ...threadService.dependencies,
+        "action",
         "mail.activity",
         "mail.attachment",
         "mail.chat_window",
diff --git a/addons/mail/static/tests/discuss_app/discuss_tests.js b/addons/mail/static/tests/discuss_app/discuss_tests.js
index 32daf48d37a..b1426ff3af4 100644
--- a/addons/mail/static/tests/discuss_app/discuss_tests.js
+++ b/addons/mail/static/tests/discuss_app/discuss_tests.js
@@ -1835,3 +1835,36 @@ QUnit.test(
         assert.strictEqual($(".o_breadcrumb").text(), "DiscussGeneral");
     }
 );
+
+QUnit.test(
+    "Chatter notification in messaging menu should open the form view even when discuss app is open",
+    async (assert) => {
+        const pyEnv = await startServer();
+        const partnerId = pyEnv["res.partner"].create({ name: "TestPartner" });
+        const messageId = pyEnv["mail.message"].create({
+            model: "res.partner",
+            body: "A needaction message to have it in messaging menu",
+            author_id: pyEnv.odoobotId,
+            needaction: true,
+            needaction_partner_ids: [pyEnv.currentPartnerId],
+            res_id: partnerId,
+        });
+        pyEnv["mail.notification"].create({
+            mail_message_id: messageId,
+            notification_status: "sent",
+            notification_type: "inbox",
+            res_partner_id: pyEnv.currentPartnerId,
+        });
+        const { openDiscuss } = await start();
+        await openDiscuss();
+        await click(".o_main_navbar i[aria-label='Messages']");
+        await click(".o-mail-NotificationItem");
+        assert.containsNone($, ".o-mail-Discuss");
+        assert.containsOnce($, ".o_form_view .o-mail-Chatter");
+        assert.containsOnce($, ".o_form_view .o_breadcrumb:contains(TestPartner)");
+        assert.containsOnce(
+            $,
+            ".o-mail-Chatter .o-mail-Message:contains(A needaction message to have it in messaging menu)"
+        );
+    }
+);