Removed display styles when hiding the fly out navigation

Closes #36224

app/assets/javascripts/fly_out_nav.js

@@ -49,7 +49,8 @@ export const hideSubLevelItems = (el) => {
 
   el.classList.remove('is-showing-fly-out');
   el.classList.remove('is-over');
-  subItems.style.display = 'none';
+  subItems.style.display = '';
+  subItems.style.transform = '';
   subItems.classList.remove('is-above');
 };
 

spec/javascripts/fly_out_nav_spec.js

@@ -59,7 +59,7 @@ describe('Fly out sidebar navigation', () => {
 
       expect(
         el.querySelector('.sidebar-sub-level-items').style.display,
-      ).toBe('none');
+      ).toBe('');
     });
 
     it('does not hude subitems on mobile', () => {