diff --git a/class/init.php b/class/init.php
index cba5582..427c680 100644
--- a/class/init.php
+++ b/class/init.php
@@ -2,16 +2,16 @@
 /**
  * Includes the main Class of the Plugin.
  * 
- * ***********************************************************************************************
- * IMPORTANT: In registerPublic() line 134: keep plugin version # up to date for cache busting.  *
- * ***********************************************************************************************
+ * ******************************************************************************************************
+ * IMPORTANT: In registerPublic() line 134: Please keep plugin version # up to date for cache busting.  *
+ * ******************************************************************************************************
  *
  * @filesource
  * @author Stefan Herndler
  * @since 1.5.0 12.09.14 10:56
  * 
  * Edited for v1.6.5: Replaced deprecated function create_function()
- * Edited for v2.0.0: Added jQueryUI from CDN   2020-10-26T1907+0100
+ * Edited for v2.0.0: Added jQueryUI from Cloudflare   2020-10-26T1907+0100
  * Edited for v2.0.3: Added style sheet versioning   2020-10-29T1413+0100
  * Edited for v2.0.4: Added jQuery UI from WordPress   2020-11-01T1902+0100
  * 
@@ -108,7 +108,8 @@ class MCI_Footnotes {
      * @author Stefan Herndler
      * @since 1.5.0
      * 
-     * Updated for v2.0.4 by adding jQueryUI from WordPress following @check2020de:
+     * Updated for v2.0.0 adding jQuery UI
+     * Updated for v2.0.4 by adding jQuery UI from WordPress following @check2020de:
      * <https://wordpress.org/support/topic/gdpr-issue-with-jquery/>
      * See <https://wordpress.stackexchange.com/questions/273986/correct-way-to-enqueue-jquery-ui>
      * 
@@ -116,24 +117,40 @@ class MCI_Footnotes {
      */
     public function registerPublic() {
         
-        // add the jQuery plugin (already registered by WordPress)
+        ###  SCRIPTS
+        
+        // add the jQuery plugin registered by WordPress
         wp_enqueue_script( 'jquery' );
-        // Add jQueryUI: 'no need to enqueue -core, because dependencies are set'
+        
+        // Add the jQuery UI libraries registered by WordPress:
+        // 'no need to enqueue -core, because dependencies are set'
+        // Source: <https://wordpress.stackexchange.com/questions/273986/correct-way-to-enqueue-jquery-ui>
         wp_enqueue_script( 'jquery-ui-widget' );
         wp_enqueue_script( 'jquery-ui-mouse' );
         wp_enqueue_script( 'jquery-ui-accordion' );
         wp_enqueue_script( 'jquery-ui-autocomplete' );
         wp_enqueue_script( 'jquery-ui-slider' );
         
+        // Should that not work, fetch jQuery UI from cdnjs.cloudflare.com:
+        // Add jQuery UI following @vonpiernik:
+        // <https://wordpress.org/support/topic/tooltip-hover-not-showing/#post-13456762>:
+        // This was enabled in Footnotes v2.0.0 through v2.0.3.
+        // Re-added for 2.0.9d1 to look whether it can fix a broken tooltip display.   2020-11-07T1601+0100
+        wp_register_script( 'jQueryUI', 'https://cdnjs.cloudflare.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.js', null, null, true );
+        wp_enqueue_script( 'jQueryUI' );
+
         // Add jQuery tools:
         wp_enqueue_script('mci-footnotes-js-jquery-tools', plugins_url('../js/jquery.tools.min.js', __FILE__));
         
-        // IMPORTANT: up-to-date plugin version number for cache busting:
+        
+        ###  STYLES
+        
+        // IMPORTANT: up-to-date plugin version number NEEDED for cache busting:
         wp_enqueue_style(
             'mci-footnotes-css-public',
             plugins_url('../css/public.css', __FILE__),
             '',
-            '2.0.9d0'
+            '2.0.9d1'
         );
     }
     
diff --git a/css/public.css b/css/public.css
index eb4b36c..b297bae 100755
--- a/css/public.css
+++ b/css/public.css
@@ -4,9 +4,9 @@
  * Created-Date: 15.05.14
  * Created-Time: 16:21
  * Since: 1.0
- * Version: 2.0.9d0
+ * Version: 2.0.9d1
  *
- * Last modified: 2020-11-07T1424+0100
+ * Last modified: 2020-11-07T1608+0100
  */
  
  
diff --git a/css/settings.css b/css/settings.css
index 05f1e32..6342f5b 100755
--- a/css/settings.css
+++ b/css/settings.css
@@ -4,8 +4,9 @@
  * Created-Date: 15.05.14
  * Created-Time: 16:21
  * Since: 1.0
- * Version: 2.0.9
- * Last modified: 2020-11-06T2321+0100
+ * Version: 2.0.9d1
+ *
+ * Last modified: 2020-11-07T1608+0100
  */
 
 
diff --git a/footnotes.php b/footnotes.php
index 6e42b1b..d8c59de 100755
--- a/footnotes.php
+++ b/footnotes.php
@@ -4,7 +4,7 @@
     Plugin URI: https://wordpress.org/plugins/footnotes/
     Description: time to bring footnotes to your website! footnotes are known from offline publishing and everybody takes them for granted when reading a magazine.
     Author: Mark Cheret
-    Version: 2.0.9d0
+    Version: 2.0.9d1
     Author URI: http://cheret.de/plugins/footnotes-2/
     Text Domain: footnotes
     Domain Path: /languages
diff --git a/readme.txt b/readme.txt
index 4141b4b..e64ca30 100755
--- a/readme.txt
+++ b/readme.txt
@@ -80,6 +80,9 @@ Visit this swift write-up from a **footnotes** user by the name of **Southwest**
 
 == Changelog ==
 
+= 2.0.9d1 =
+- Bugfix: Re-added jQuery UI from third party to look whether it can fix a broken tooltip display   2020-11-07T1604+0100
+
 = 2.0.9d0 =
 - Bugfix: Layout: Footnote referrers: more efficiently disable underline unless hovered