diff --git a/CHANGES.md b/CHANGES.md
index 18b21ff4eb1..a7ff2302367 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -6,6 +6,8 @@ Changes
 
 ### Unreleased
 
+* 2024-11-19 - Bugfix: The starred courses popover showed a JavaScript error in the browser JS console, resolves #759.
+* 2024-11-19 - Bugfix: The starred courses popover in the navbar must only be shown if Boost Union or Boost Union child is active, resolves #759.
 * 2024-11-18 - Improvement: Add the possibility to restrict smart menus and smart menu items to site admins and non-site admins only, resolves #421.
 * 2024-11-18 - Bugfix: Footer displacement on pages with minimal content, resolves #655.
 * 2024-11-18 - Upstream change: Adopt changes from MDL-77732 ('Custom menu items do not receive active behaviour'), resolves #436 #620 #384 #715.
diff --git a/locallib.php b/locallib.php
index 7b15874aecb..426093e2882 100644
--- a/locallib.php
+++ b/locallib.php
@@ -1934,6 +1934,12 @@ function theme_boost_union_yesno_to_boolstring($var) {
 function theme_boost_union_get_navbar_starredcoursespopover() {
     global $USER, $OUTPUT;
 
+    // If a theme other than Boost Union or a child theme of it is active, return directly.
+    // This is necessary as the callback is called regardless of the active theme.
+    if (theme_boost_union_is_active_theme() != true) {
+        return '';
+    }
+
     // The popover is relevant only for logged-in users. If the user is not logged in, return directly.
     if (!isloggedin()) {
         return '';
@@ -2033,7 +2039,7 @@ function($favourite) {
  * @return string|void The legacy implementation will return a string, the hook implementation will return nothing.
  */
 function theme_boost_union_callbackimpl_before_standard_html(&$hook = null) {
-    global $CFG, $PAGE;
+    global $CFG;
 
     // Require local library.
     require_once($CFG->dirroot.'/theme/boost_union/locallib.php');
@@ -2043,7 +2049,7 @@ function theme_boost_union_callbackimpl_before_standard_html(&$hook = null) {
 
     // If a theme other than Boost Union or a child theme of it is active, return directly.
     // This is necessary as the callback is called regardless of the active theme.
-    if ($PAGE->theme->name != 'boost_union' && !in_array('boost_union', $PAGE->theme->parents)) {
+    if (theme_boost_union_is_active_theme() != true) {
         if ($hook != null) {
             return;
         } else {
@@ -2412,3 +2418,19 @@ function theme_boost_union_remove_hookmanipulation() {
     // Remove the hook overrides.
     $cache->delete('overrides');
 }
+
+/**
+ * Helper function to check if Boost Union or a child theme of Boost Union is active.
+ * This is needed at multiple locations to avoid that callbacks in Boost Union affect other active themes.
+ *
+ * @return bool
+ */
+function theme_boost_union_is_active_theme() {
+    global $PAGE;
+
+    if ($PAGE->theme->name == 'boost_union' || in_array('boost_union', $PAGE->theme->parents)) {
+        return true;
+    } else {
+        return false;
+    }
+}
diff --git a/templates/popover-favourites.mustache b/templates/popover-favourites.mustache
index 6e13e83223d..e6b8157255f 100644
--- a/templates/popover-favourites.mustache
+++ b/templates/popover-favourites.mustache
@@ -60,7 +60,6 @@
 require(['jquery', 'core/popover_region_controller'], function($, Controller) {
     var container = $('#nav-popover-favourites-container');
     var controller = new Controller(container);
-    controller.registerEventListeners();
     controller.registerListNavigationEventListeners();
 });
 {{/js}}