diff --git a/src/wwwroot/Extensions.MudBlazor.StaticInput.lib.module.js b/src/wwwroot/Extensions.MudBlazor.StaticInput.lib.module.js
index 50787b1..f26a5ef 100644
--- a/src/wwwroot/Extensions.MudBlazor.StaticInput.lib.module.js
+++ b/src/wwwroot/Extensions.MudBlazor.StaticInput.lib.module.js
@@ -1,4 +1,6 @@
 
+const initializedElements = new WeakSet();
+
 export function afterWebStarted(blazor) {
     if (blazor) {
         blazor.addEventListener('enhancedload', () => {
@@ -35,8 +37,11 @@ function initialize() {
 }
 
 function initTextFields() {
-    const textFields = document.querySelectorAll('[data-mud-static-type="text-field"]:not([data-mud-static-initialized="true"])');
+    const textFields = document.querySelectorAll('[data-mud-static-type="text-field"]');
     textFields.forEach(inputElement => {
+        if (initializedElements.has(inputElement)) return;
+        initializedElements.add(inputElement);
+
         inputElement.setAttribute('data-mud-static-initialized', 'true');
         const shrinkLabel = inputElement.getAttribute('data-mud-static-shrink') === 'true';
         const showOnFocus = inputElement.getAttribute('data-mud-static-helper-focus') === 'true';
@@ -103,8 +108,11 @@ function initTextFields() {
 }
 
 function initCheckBoxes() {
-    const checkBoxes = document.querySelectorAll('[data-mud-static-type="checkbox"]:not([data-mud-static-initialized="true"])');
+    const checkBoxes = document.querySelectorAll('[data-mud-static-type="checkbox"]');
     checkBoxes.forEach(checkbox => {
+        if (initializedElements.has(checkbox)) return;
+        initializedElements.add(checkbox);
+
         checkbox.setAttribute('data-mud-static-initialized', 'true');
         const name = checkbox.getAttribute('data-mud-static-name');
         const parent = checkbox.closest('.mud-input-control');
@@ -132,8 +140,11 @@ function initCheckBoxes() {
 }
 
 function initSwitches() {
-    const switches = document.querySelectorAll('[data-mud-static-type="switch"]:not([data-mud-static-initialized="true"])');
+    const switches = document.querySelectorAll('[data-mud-static-type="switch"]');
     switches.forEach(switchToggle => {
+        if (initializedElements.has(switchToggle)) return;
+        initializedElements.add(switchToggle);
+
         switchToggle.setAttribute('data-mud-static-initialized', 'true');
         const name = switchToggle.getAttribute('data-mud-static-name');
         const label = switchToggle.closest('label');
@@ -180,8 +191,11 @@ function initSwitches() {
 }
 
 function initRadios() {
-    const radios = document.querySelectorAll('[data-mud-static-type="radio"]:not([data-mud-static-initialized="true"])');
+    const radios = document.querySelectorAll('[data-mud-static-type="radio"]');
     radios.forEach(radio => {
+        if (initializedElements.has(radio)) return;
+        initializedElements.add(radio);
+
         radio.setAttribute('data-mud-static-initialized', 'true');
         radio.addEventListener('change', function () {
             const parentGroup = radio.closest('[data-mud-static-type="radio-group"]');
@@ -223,8 +237,11 @@ function initRadios() {
 }
 
 function initDrawers() {
-    const drawerToggleElements = document.querySelectorAll('[data-mud-static-type="drawer-toggle"]:not([data-mud-static-initialized="true"])');
+    const drawerToggleElements = document.querySelectorAll('[data-mud-static-type="drawer-toggle"]');
     drawerToggleElements.forEach(element => {
+        if (initializedElements.has(element)) return;
+        initializedElements.add(element);
+
         element.setAttribute('data-mud-static-initialized', 'true');
         element.removeEventListener('click', onDrawerToggleClick);
         element.addEventListener('click', onDrawerToggleClick);
@@ -500,8 +517,11 @@ function autoExpand(mudDrawer, variant, breakpoint, position) {
 }
 
 function initNavGroups() {
-    const navGroups = document.querySelectorAll('[data-mud-static-type="nav-group"]:not([data-mud-static-initialized="true"])');
+    const navGroups = document.querySelectorAll('[data-mud-static-type="nav-group"]');
     navGroups.forEach(navGroup => {
+        if (initializedElements.has(navGroup)) return;
+        initializedElements.add(navGroup);
+
         navGroup.setAttribute('data-mud-static-initialized', 'true');
         const button = navGroup.querySelector('button');
         if (button) {
@@ -510,18 +530,58 @@ function initNavGroups() {
                 if (!navElement) return;
                 const collapseContainer = navElement.querySelector('.mud-collapse-container');
                 const expandIcon = navElement.querySelector('.mud-nav-link-expand-icon');
+                const wrapper = collapseContainer ? collapseContainer.querySelector('.mud-collapse-wrapper') : null;
+
+                if (!collapseContainer || !expandIcon || !wrapper) return;
 
-                if (!collapseContainer || !expandIcon) return;
+                const isCurrentlyExpanded = button.getAttribute('aria-expanded') === "true";
+                const willExpand = !isCurrentlyExpanded;
+
+                if (collapseContainer._mudStaticNavGroupTimeout) {
+                    clearTimeout(collapseContainer._mudStaticNavGroupTimeout);
+                }
 
-                const isExpanded = button.getAttribute('aria-expanded') === "true";
+                collapseContainer.classList.remove('mud-collapse-entering', 'mud-collapse-exiting', 'mud-collapse-entered', 'invisible');
+                collapseContainer.style.transition = 'height 250ms cubic-bezier(0.4, 0, 0.2, 1)';
 
-                collapseContainer.classList.toggle('mud-collapse-entered', !isExpanded);
-                collapseContainer.classList.toggle('mud-navgroup-collapse', true);
-                collapseContainer.classList.remove('mud-collapse-entering');
-                collapseContainer.setAttribute('aria-hidden', isExpanded);
+                if (willExpand) {
+                    collapseContainer.style.display = 'block';
+                    collapseContainer.style.height = '0px';
+
+                    collapseContainer.offsetHeight;
+
+                    collapseContainer.setAttribute('aria-hidden', 'false');
+                    collapseContainer.classList.add('mud-collapse-entering');
+
+                    const height = wrapper.scrollHeight;
+                    collapseContainer.style.height = height + 'px';
+
+                    collapseContainer._mudStaticNavGroupTimeout = setTimeout(() => {
+                        collapseContainer.classList.remove('mud-collapse-entering');
+                        collapseContainer.classList.add('mud-collapse-entered');
+                        collapseContainer.style.height = 'auto';
+                        delete collapseContainer._mudStaticNavGroupTimeout;
+                    }, 250);
+                } else {
+                    const height = wrapper.scrollHeight;
+                    collapseContainer.style.height = height + 'px';
+
+                    collapseContainer.offsetHeight;
+
+                    collapseContainer.classList.add('mud-collapse-exiting');
+                    collapseContainer.style.height = '0px';
+
+                    collapseContainer._mudStaticNavGroupTimeout = setTimeout(() => {
+                        collapseContainer.classList.remove('mud-collapse-exiting');
+                        collapseContainer.classList.add('invisible');
+                        collapseContainer.style.display = '';
+                        collapseContainer.setAttribute('aria-hidden', 'true');
+                        delete collapseContainer._mudStaticNavGroupTimeout;
+                    }, 250);
+                }
 
-                expandIcon.classList.toggle('mud-transform', !isExpanded);
-                button.setAttribute('aria-expanded', !isExpanded);
+                expandIcon.classList.toggle('mud-transform', willExpand);
+                button.setAttribute('aria-expanded', willExpand);
             });
         }
     });
diff --git a/tests/StaticInput.UnitTests/Components/NavMenuTests.cs b/tests/StaticInput.UnitTests/Components/NavMenuTests.cs
index 07ac1f1..40b1b84 100644
--- a/tests/StaticInput.UnitTests/Components/NavMenuTests.cs
+++ b/tests/StaticInput.UnitTests/Components/NavMenuTests.cs
@@ -27,17 +27,23 @@ public async Task Group_Collapses_Expands_On_Click()
             ariaValue.Should().Be("false");
 
             await button.ClickAsync();
+            // Wait for JS animation
+            await Task.Delay(600);
 
             menuClasses = await menuGroup.GetAttributeAsync("class");
-            menuClasses.Should().NotContain("mud-collapse-entered").And.NotContain("mud-collapse-entering");
+            menuClasses.Should().NotContain("mud-collapse-entered");
+            menuClasses.Should().Contain("invisible");
 
             ariaValue = await menuGroup.GetAttributeAsync("aria-hidden");
             ariaValue.Should().Be("true");
 
             await button.ClickAsync();
+            // Wait for JS animation
+            await Task.Delay(600);
 
             menuClasses = await menuGroup.GetAttributeAsync("class");
             menuClasses.Should().Contain("mud-collapse-entered");
+            menuClasses.Should().NotContain("invisible");
 
             ariaValue = await menuGroup.GetAttributeAsync("aria-hidden");
             ariaValue.Should().Be("false");