diff --git a/core/src/client/ProductNavigation/app.tsx b/core/src/client/ProductNavigation/app.tsx
index 4f1cd00b110..056d953982b 100644
--- a/core/src/client/ProductNavigation/app.tsx
+++ b/core/src/client/ProductNavigation/app.tsx
@@ -4,11 +4,14 @@
  * Licensed under the Apache License, Version 2.0: http://www.apache.org/licenses/LICENSE-2.0
  */
 import React from 'react';
-import { createRoot } from 'react-dom/client';
+import { createRoot, Root } from 'react-dom/client';
 import { App } from '@labkey/api';
 
 import { AppContext, ProductNavigation } from './ProductNavigation';
 
+let root: Root;
+
 App.registerApp<AppContext>('productNavigation', (target, ctx) => {
-    createRoot(document.getElementById(target)).render(<ProductNavigation context={ctx} />);
+    if (!root) root = createRoot(document.getElementById(target));
+    root.render(<ProductNavigation context={ctx} />);
 });
diff --git a/core/src/org/labkey/core/view/template/bootstrap/header.jsp b/core/src/org/labkey/core/view/template/bootstrap/header.jsp
index c43d52c28f5..a3c2fd3bd0c 100644
--- a/core/src/org/labkey/core/view/template/bootstrap/header.jsp
+++ b/core/src/org/labkey/core/view/template/bootstrap/header.jsp
@@ -214,7 +214,9 @@
                     <i class="fa fa-th-large" style="font-size: 18px; padding-top: 2px;"></i>
                 </a>
                 <ul class="dropdown-menu dropdown-menu-right">
-                    <div id="headerProductDropdown-content"></div>
+                    <li id="headerProductDropdown-content">
+                        <div role="status" style="padding: 10px;"><i aria-hidden="true" class="fa fa-spinner fa-pulse"></i> Loading...</div>
+                    </li>
                 </ul>
             </li>
 <%
diff --git a/core/webapp/core/ProductNavigationHeader.js b/core/webapp/core/ProductNavigationHeader.js
index 06f67b458e8..f9e4b326f2c 100644
--- a/core/webapp/core/ProductNavigationHeader.js
+++ b/core/webapp/core/ProductNavigationHeader.js
@@ -5,38 +5,44 @@
  */
 (function ($)
 {
-    var HEADER_ID_PREFIX = 'headerProductDropdown';
-    var HEADER_CONTENT_ID = HEADER_ID_PREFIX + '-content';
+    const HEADER_ID_PREFIX = 'headerProductDropdown';
+    const HEADER_CONTENT_ID = HEADER_ID_PREFIX + '-content';
+    let scriptRequested = false;
+    let scriptLoaded = false;
+    let menuOpen = false;
 
-    // wait to load the product navigation dependencies until the hover over the header icon
-    var productNavLoaded = false;
-    $(document).on('mouseenter', '#' + HEADER_ID_PREFIX + ' .dropdown-toggle', function(e) {
-        if (!productNavLoaded) {
-            $("#" + HEADER_CONTENT_ID).html("<div style=\"padding: 10px;\"><i class=\"fa fa-spinner fa-pulse\"></i> Loading...</div>");
+    function showProductMenu(show) {
+        LABKEY.App.loadApp('productNavigation', HEADER_CONTENT_ID, { show });
+    }
 
-            LABKEY.requiresScript('gen/productNavigation', loadProductNav);
-            // LABKEY.requiresScript('http://localhost:3001/productNavigation.js', loadProductNav);
-        } else {
-            loadProductNav();
-        }
+    function onLoad() {
+        scriptLoaded = true;
+        if (menuOpen) showProductMenu(true);
+    }
+
+    function requireProductNav() {
+        if (scriptRequested) return;
+        scriptRequested = true;
+        LABKEY.requiresScript('gen/productNavigation', onLoad);
+        // LABKEY.requiresScript('http://localhost:3001/productNavigation.js', onLoad);
+    }
+
+    // preload on hover/focus so the menu is usually ready by the time it opens
+    $(document).on('mouseenter focusin', '#' + HEADER_ID_PREFIX + ' .dropdown-toggle', requireProductNav);
+
+    $(document).on('show.bs.dropdown', '#' + HEADER_ID_PREFIX, function () {
+        menuOpen = true;
+        requireProductNav();
+        if (scriptLoaded) showProductMenu(true);
     });
 
-    var loadProductNav = function() {
-        LABKEY.App.loadApp('productNavigation', HEADER_CONTENT_ID, { show: true });
-        $(document).on('click', addProductNavClickHandler);
-        productNavLoaded = true;
-    };
+    $(document).on('hidden.bs.dropdown', '#' + HEADER_ID_PREFIX, function () {
+        menuOpen = false;
+        if (scriptLoaded) showProductMenu(false);
+    });
 
     // stop the product navigation menu from closing when click within the menu div
     $(document).on('click', '#' + HEADER_CONTENT_ID, function (e) {
         e.stopPropagation();
     });
-
-    // on click outside of the open menu, remove click handler and hide menu (which will force it to reset on next open)
-    var addProductNavClickHandler = function (e) {
-        if ($(e.target).closest(HEADER_CONTENT_ID).length === 0) {
-            LABKEY.App.loadApp('productNavigation', HEADER_CONTENT_ID, { show: false });
-            $(document).off('click', addProductNavClickHandler);
-        }
-    };
 })(jQuery);