Navigation Menu: Sub-menu for child items doesn't show anymore after clicking on another item in the navigation menu before next page finishes loading.

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.0 DXP GA1, 7.0.5 CE GA6, 7.0.0 DXP FP46, 7.0.X, Master
• Fix Version/s: 7.0.0 DXP FP58, 7.0.0 DXP SP9, 7.0.X, 7.1.10 DXP FP2, 7.1.1 CE GA2, 7.1.10.1 SP1, 7.1.X, Master
• Component/s: Frontend Infrastructure
• Labels:
  • 7.1-could
  • INACTIVE
  • QA-V
  • ee-ts
  • liferay-dxp-70-sp9
  • liferay-dxp-71-sp1
  • liferay-fixpack-de-58-7010
  • liferay-fixpack-dxp-2-7110
• Branch Version/s:
  7.1.x, 7.0.x
• Backported to Branch:
  Committed
• Story Points: 1
• Fix Priority: 3
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/62463

STEPS TO REPRODUCE:

Precondition: Create a fresh Liferay instance.

1. As an administrator create a page with one child page on the Default Site.
2. Close the session to render the page as a guest.
3. In the Navigation Menu portlet on the top of the page, hover the mouse over the created page. The child page link appears in a sub-menu item.
4. Click on the child page link.
5. As soon as you click on the link, immediately click on the "Welcome" link in the Navigation Bar. You must do this action before the next page loads.
6. Repeat step 3.

Expected Result:
The sub-menu with the child page link appears.

Actual Result:
The sub-menu doesn't appear, breaking the navigation menu.

Notes:

• The Liferay Portal seems to load slower in Internet Explorer 11 than in other browsers. Using this particular browser in combination with a moderate connection speed causes this bug to be reproducible most of the time, forcing the user to reload the page and wait on every navigation action until the page loads.
• I'm attaching the bug evidence in both Liferay CE and Liferay DXP.