diff --git a/app/assets/javascripts/discourse/app/components/d-editor.js b/app/assets/javascripts/discourse/app/components/d-editor.js
index 64175e030fa..a622955b4c6 100644
--- a/app/assets/javascripts/discourse/app/components/d-editor.js
+++ b/app/assets/javascripts/discourse/app/components/d-editor.js
@@ -464,9 +464,11 @@ export default Component.extend(TextareaTextManipulation, {
       this.site.hashtag_configurations["topic-composer"],
       this._$textarea,
       this.siteSettings,
-      (value) => {
-        this.set("value", value);
-        schedule("afterRender", this, this.focusTextArea);
+      {
+        afterComplete: (value) => {
+          this.set("value", value);
+          schedule("afterRender", this, this.focusTextArea);
+        },
       }
     );
   },
diff --git a/app/assets/javascripts/discourse/app/lib/hashtag-autocomplete.js b/app/assets/javascripts/discourse/app/lib/hashtag-autocomplete.js
index 14b6e870a25..4d7129ea0c0 100644
--- a/app/assets/javascripts/discourse/app/lib/hashtag-autocomplete.js
+++ b/app/assets/javascripts/discourse/app/lib/hashtag-autocomplete.js
@@ -27,23 +27,30 @@ import { htmlSafe } from "@ember/template";
  * @param {$Element} $textarea - jQuery element to use for the autocompletion
  *   plugin to attach to, this is what will watch for the # matcher when the user is typing.
  * @param {Hash} siteSettings - The clientside site settings.
- * @param {Function} afterComplete - Called with the selected autocomplete option once it is selected.
+ * @param {Function} autocompleteOptions - Options to pass to the jQuery plugin. Must at least include:
+ *
+ *  - afterComplete - Called with the selected autocomplete option once it is selected.
+ *
+ *  Can also include:
+ *
+ *  - treatAsTextarea - Whether to anchor the autocompletion to the start of the input and
+ *                      ensure the popper is always on top.
  **/
 export function setupHashtagAutocomplete(
   contextualHashtagConfiguration,
   $textArea,
   siteSettings,
-  afterComplete
+  autocompleteOptions = {}
 ) {
   if (siteSettings.enable_experimental_hashtag_autocomplete) {
     _setupExperimental(
       contextualHashtagConfiguration,
       $textArea,
       siteSettings,
-      afterComplete
+      autocompleteOptions
     );
   } else {
-    _setup($textArea, siteSettings, afterComplete);
+    _setup($textArea, siteSettings, autocompleteOptions.afterComplete);
   }
 }
 
@@ -123,13 +130,14 @@ function _setupExperimental(
   contextualHashtagConfiguration,
   $textArea,
   siteSettings,
-  afterComplete
+  autocompleteOptions
 ) {
   $textArea.autocomplete({
     template: findRawTemplate("hashtag-autocomplete"),
     key: "#",
-    afterComplete,
-    treatAsTextarea: $textArea[0].tagName === "INPUT",
+    afterComplete: autocompleteOptions.afterComplete,
+    treatAsTextarea: autocompleteOptions.treatAsTextarea,
+    autoSelectFirstSuggestion: true,
     transformComplete: (obj) => obj.ref,
     dataSource: (term) => {
       if (term.match(/\s/)) {
diff --git a/plugins/chat/assets/javascripts/discourse/components/chat-composer.js b/plugins/chat/assets/javascripts/discourse/components/chat-composer.js
index 0edc60c7607..1ce08f09700 100644
--- a/plugins/chat/assets/javascripts/discourse/components/chat-composer.js
+++ b/plugins/chat/assets/javascripts/discourse/components/chat-composer.js
@@ -410,9 +410,12 @@ export default Component.extend(TextareaTextManipulation, {
       this.site.hashtag_configurations["chat-composer"],
       $textarea,
       this.siteSettings,
-      (value) => {
-        this.set("value", value);
-        return this._focusTextArea();
+      {
+        treatAsTextarea: true,
+        afterComplete: (value) => {
+          this.set("value", value);
+          return this._focusTextArea();
+        },
       }
     );
   },