diff --git a/app/assets/javascripts/discourse/app/components/d-editor.js b/app/assets/javascripts/discourse/app/components/d-editor.js
index b8e6362d31e..0e1ed221c65 100644
--- a/app/assets/javascripts/discourse/app/components/d-editor.js
+++ b/app/assets/javascripts/discourse/app/components/d-editor.js
@@ -484,8 +484,8 @@ export default class DEditor extends Component {
         destroyUserStatuses();
         return userSearch({
           term,
-          topicId: this.topic?.id,
-          categoryId: this.topic?.category_id || this.composer?.categoryId,
+          topicId: this.topicId,
+          categoryId: this.categoryId,
           includeGroups: true,
         }).then((result) => {
           initUserStatusHtml(getOwner(this), result.users);
diff --git a/app/assets/javascripts/discourse/tests/acceptance/composer-editor-mentions-test.js b/app/assets/javascripts/discourse/tests/acceptance/composer-editor-mentions-test.js
index 08e8b860fb5..ac0c64f2bd1 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/composer-editor-mentions-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/composer-editor-mentions-test.js
@@ -1,6 +1,7 @@
 import { click, visit } from "@ember/test-helpers";
 import { test } from "qunit";
 import { setCaretPosition } from "discourse/lib/utilities";
+import topicFixtures from "discourse/tests/fixtures/topic";
 import {
   acceptance,
   fakeTime,
@@ -9,6 +10,7 @@ import {
   queryAll,
   simulateKeys,
 } from "discourse/tests/helpers/qunit-helpers";
+import { cloneJSON } from "discourse-common/lib/object";
 
 acceptance("Composer - editor mentions", function (needs) {
   let clock = null;
@@ -24,6 +26,11 @@ acceptance("Composer - editor mentions", function (needs) {
   needs.hooks.afterEach(() => clock?.restore());
 
   needs.pretender((server, helper) => {
+    server.get("/t/11557.json", () => {
+      const topicFixture = cloneJSON(topicFixtures["/t/130.json"]);
+      topicFixture.id = 11557;
+      return helper.response(topicFixture);
+    });
     server.get("/u/search/users", () => {
       return helper.response({
         users: [
@@ -144,4 +151,19 @@ acceptance("Composer - editor mentions", function (needs) {
       ["foo", "user_group", "user", "user2"]
     );
   });
+
+  test("shows users immediately when @ is typed in a reply", async function (assert) {
+    await visit("/");
+    await click(".topic-list-item .title");
+    await click(".btn-primary.create");
+
+    await simulateKeys(".d-editor-input", "abc @");
+
+    assert.deepEqual(
+      [...document.querySelectorAll(".ac-user .username")].map(
+        (e) => e.innerText
+      ),
+      ["user_group", "user", "user2", "foo"]
+    );
+  });
 });