diff --git a/addons/website_livechat/static/src/web/discuss_app_category_model_patch.js b/addons/im_livechat/static/src/core/web/discuss_app_category_model_patch.js
similarity index 68%
rename from addons/website_livechat/static/src/web/discuss_app_category_model_patch.js
rename to addons/im_livechat/static/src/core/web/discuss_app_category_model_patch.js
index a781ff68abb..629755f9207 100644
--- a/addons/website_livechat/static/src/web/discuss_app_category_model_patch.js
+++ b/addons/im_livechat/static/src/core/web/discuss_app_category_model_patch.js
@@ -2,6 +2,7 @@
 
 import { patch } from "@web/core/utils/patch";
 import { DiscussAppCategory } from "@mail/core/common/discuss_app_category_model";
+import { compareDatetime } from "@mail/utils/common/misc";
 
 patch(DiscussAppCategory.prototype, {
     /**
@@ -10,7 +11,9 @@ patch(DiscussAppCategory.prototype, {
      */
     sortThreads(t1, t2) {
         if (this.id === "livechat") {
-            return t2.lastInterestDateTime?.ts - t1.lastInterestDateTime?.ts;
+            return (
+                compareDatetime(t2.lastInterestDateTime, t1.lastInterestDateTime) || t2.id - t1.id
+            );
         }
         return super.sortThreads(t1, t2);
     },
diff --git a/addons/im_livechat/static/src/core/web/thread_service_patch.js b/addons/im_livechat/static/src/core/web/thread_service_patch.js
index aa59cff9944..008ac56a499 100644
--- a/addons/im_livechat/static/src/core/web/thread_service_patch.js
+++ b/addons/im_livechat/static/src/core/web/thread_service_patch.js
@@ -1,6 +1,7 @@
 /* @odoo-module */
 
 import { ThreadService } from "@mail/core/common/thread_service";
+import { compareDatetime } from "@mail/utils/common/misc";
 
 import { patch } from "@web/core/utils/patch";
 
@@ -33,7 +34,8 @@ patch(ThreadService.prototype, {
         super.sortChannels();
         // Live chats are sorted by most recent interest date time in the sidebar.
         this.store.discuss.livechat.threads.sort(
-            (t1, t2) => t2.lastInterestDateTime?.ts - t1.lastInterestDateTime?.ts
+            (t1, t2) =>
+                compareDatetime(t2.lastInterestDateTime, t1.lastInterestDateTime) || t2.id - t1.id
         );
     },
 
@@ -43,7 +45,11 @@ patch(ThreadService.prototype, {
     goToOldestUnreadLivechatThread() {
         const oldestUnreadThread = this.store.discuss.livechat.threads
             .filter((thread) => thread.isUnread)
-            .sort((t1, t2) => t1.lastInterestDateTime?.ts - t2.lastInterestDateTime?.ts)[0];
+            .sort(
+                (t1, t2) =>
+                    compareDatetime(t1.lastInterestDateTime, t2.lastInterestDateTime) ||
+                    t1.id - t2.id
+            )[0];
         if (!oldestUnreadThread) {
             return false;
         }
diff --git a/addons/mail/static/src/core/common/discuss_app_category_model.js b/addons/mail/static/src/core/common/discuss_app_category_model.js
index 4f2730e4004..3ca0aa4b519 100644
--- a/addons/mail/static/src/core/common/discuss_app_category_model.js
+++ b/addons/mail/static/src/core/common/discuss_app_category_model.js
@@ -1,5 +1,6 @@
 /* @odoo-module */
 
+import { compareDatetime } from "@mail/utils/common/misc";
 import { Record } from "./record";
 
 export class DiscussAppCategory extends Record {
@@ -22,7 +23,9 @@ export class DiscussAppCategory extends Record {
             return String.prototype.localeCompare.call(t1.name, t2.name);
         }
         if (this.id === "chats") {
-            return t2.lastInterestDateTime.ts - t1.lastInterestDateTime.ts;
+            return (
+                compareDatetime(t2.lastInterestDateTime, t1.lastInterestDateTime) || t2.id - t1.id
+            );
         }
     }
 
diff --git a/addons/mail/static/src/core/common/persona_service.js b/addons/mail/static/src/core/common/persona_service.js
index 58b0abdb955..b5ff84e0024 100644
--- a/addons/mail/static/src/core/common/persona_service.js
+++ b/addons/mail/static/src/core/common/persona_service.js
@@ -3,6 +3,7 @@
 import { registry } from "@web/core/registry";
 import { useSequential } from "@mail/utils/common/hooks";
 import { markRaw } from "@odoo/owl";
+import { compareDatetime } from "@mail/utils/common/misc";
 
 export const DEFAULT_AVATAR = "/mail/static/src/img/smiley/avatar.jpg";
 
@@ -83,19 +84,10 @@ export class PersonaService {
     getRecentChatPartnerIds() {
         return Object.values(this.store.Thread.records)
             .filter((thread) => thread.type === "chat")
-            .sort((a, b) => {
-                const [a_dt , b_dt] = [a.lastInterestDateTime, b.lastInterestDateTime]
-                if (!a_dt && !b_dt) {
-                    return 0;
-                }
-                if (a_dt && !b_dt) {
-                    return -1;
-                }
-                if (!a_dt && b_dt) {
-                    return 1;
-                }
-                return b_dt.ts - a_dt.ts;
-            })
+            .sort(
+                (a, b) =>
+                    compareDatetime(b.lastInterestDateTime, a.lastInterestDateTime) || b.id - a.id
+            )
             .map((thread) => thread.chatPartner?.id);
     }
 }
diff --git a/addons/mail/static/src/core/common/thread_service.js b/addons/mail/static/src/core/common/thread_service.js
index bc214be2b3e..56ee60be5e6 100644
--- a/addons/mail/static/src/core/common/thread_service.js
+++ b/addons/mail/static/src/core/common/thread_service.js
@@ -11,6 +11,7 @@ import { registry } from "@web/core/registry";
 import { memoize } from "@web/core/utils/functions";
 import { url } from "@web/core/utils/urls";
 import { escape } from "@web/core/utils/strings";
+import { compareDatetime } from "@mail/utils/common/misc";
 
 const FETCH_LIMIT = 30;
 
@@ -429,7 +430,8 @@ export class ThreadService {
             String.prototype.localeCompare.call(t1.name, t2.name)
         );
         this.store.discuss.chats.threads.sort(
-            (t1, t2) => t2.lastInterestDateTime.ts - t1.lastInterestDateTime.ts
+            (t1, t2) =>
+                compareDatetime(t2.lastInterestDateTime, t1.lastInterestDateTime) || t2.id - t1.id
         );
     }
 
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 ed96a39ab0d..67a4b26a8d9 100644
--- a/addons/mail/static/src/core/web/thread_service_patch.js
+++ b/addons/mail/static/src/core/web/thread_service_patch.js
@@ -6,6 +6,7 @@ import { parseEmail } from "@mail/js/utils";
 import { _t } from "@web/core/l10n/translation";
 import { patch } from "@web/core/utils/patch";
 import { Record } from "@mail/core/common/record";
+import { compareDatetime } from "@mail/utils/common/misc";
 
 let nextId = 1;
 
@@ -241,18 +242,10 @@ patch(ThreadService.prototype, {
     getRecentChannels() {
         return Object.values(this.store.Thread.records)
             .filter((thread) => thread.model === "discuss.channel")
-            .sort((a, b) => {
-                if (a.lastInterestDateTime?.ts !== b.lastInterestDateTime?.ts) {
-                    if (!b.lastInterestDateTime) {
-                        return -1;
-                    }
-                    if (!a.lastInterestDateTime) {
-                        return 1;
-                    }
-                    return b.lastInterestDateTime.ts - a.lastInterestDateTime.ts;
-                }
-                return a.id - b.id;
-            });
+            .sort(
+                (a, b) =>
+                    compareDatetime(b.lastInterestDateTime, a.lastInterestDateTime) || b.id - a.id
+            );
     },
     getNeedactionChannels() {
         return this.getRecentChannels().filter((channel) => this.getCounter(channel) > 0);
diff --git a/addons/mail/static/src/utils/common/misc.js b/addons/mail/static/src/utils/common/misc.js
index 788479dc7f2..5bc52ddf52a 100644
--- a/addons/mail/static/src/utils/common/misc.js
+++ b/addons/mail/static/src/utils/common/misc.js
@@ -69,3 +69,24 @@ export function onChange(target, key, callback) {
 export function closeStream(stream) {
     stream?.getTracks?.().forEach((track) => track.stop());
 }
+
+/**
+ * Compare two Luxon datetime.
+ *
+ * @param {import("@web/core/l10n/dates").NullableDateTime} date1
+ * @param {import("@web/core/l10n/dates").NullableDateTime} date2
+ * @returns {number} Negative if date1 is less than date2, positive if date1 is
+ *  greater than date2, and 0 if they are equal.
+ */
+export function compareDatetime(date1, date2) {
+    if (date1?.ts === date2?.ts) {
+        return 0;
+    }
+    if (!date1) {
+        return -1;
+    }
+    if (!date2) {
+        return 1;
+    }
+    return date1.ts - date2.ts;
+}
diff --git a/addons/mail/static/tests/discuss/core/suggestion_tests.js b/addons/mail/static/tests/discuss/core/suggestion_tests.js
index 928ca48ef0a..8bf00714888 100644
--- a/addons/mail/static/tests/discuss/core/suggestion_tests.js
+++ b/addons/mail/static/tests/discuss/core/suggestion_tests.js
@@ -78,12 +78,16 @@ QUnit.test("Sort partner suggestions by recent chats", async () => {
         { partner_id: partner_3 },
     ]);
     pyEnv["discuss.channel"].create([
-        { name: "General", channel_type: "channel", channel_member_ids: [
-            Command.create({ partner_id: pyEnv.currentPartnerId }),
-            Command.create({ partner_id: partner_1 }),
-            Command.create({ partner_id: partner_2 }),
-            Command.create({ partner_id: partner_3 }),
-        ]},
+        {
+            name: "General",
+            channel_type: "channel",
+            channel_member_ids: [
+                Command.create({ partner_id: pyEnv.currentPartnerId }),
+                Command.create({ partner_id: partner_1 }),
+                Command.create({ partner_id: partner_2 }),
+                Command.create({ partner_id: partner_3 }),
+            ],
+        },
         {
             channel_member_ids: [
                 Command.create({
@@ -126,8 +130,8 @@ QUnit.test("Sort partner suggestions by recent chats", async () => {
     await insertText(".o-mail-Composer-input", "User");
     await contains(".o-mail-Composer-suggestion strong", { count: 3 });
     await contains(":nth-child(1 of .o-mail-Composer-suggestion) strong", { text: "User 2" });
-    await contains(":nth-child(2 of .o-mail-Composer-suggestion) strong", { text: "User 1" });
-    await contains(":nth-child(3 of .o-mail-Composer-suggestion) strong", { text: "User 3" });
+    await contains(":nth-child(2 of .o-mail-Composer-suggestion) strong", { text: "User 3" });
+    await contains(":nth-child(3 of .o-mail-Composer-suggestion) strong", { text: "User 1" });
 });
 
 QUnit.test("mention suggestion are shown after deleting a character", async () => {
diff --git a/addons/mail/static/tests/discuss/core/web/command_palette_tests.js b/addons/mail/static/tests/discuss/core/web/command_palette_tests.js
index 1134db922e9..accdfc6d533 100644
--- a/addons/mail/static/tests/discuss/core/web/command_palette_tests.js
+++ b/addons/mail/static/tests/discuss/core/web/command_palette_tests.js
@@ -59,10 +59,10 @@ QUnit.test("open the chatWindow of a channel from the command palette", async ()
     await insertText(".o_command_palette_search input", "#");
     advanceTime(commandSetupRegistry.get("#").debounceDelay);
     await contains(".o_command", { count: 2 });
-    await contains(".o_command", { text: "general", before: [".o_command", { text: "project" }] });
+    await contains(".o_command", { text: "project", before: [".o_command", { text: "general" }] });
     await contains(".o_command.focused");
-    await click(".o_command.focused", { text: "general" });
-    await contains(".o-mail-ChatWindow", { text: "general" });
+    await click(".o_command.focused", { text: "project" });
+    await contains(".o-mail-ChatWindow", { text: "project" });
 });
 
 QUnit.test("Channel mentions in the command palette of Discuss app with @", async () => {