We cannot add Public Navigation Menu Page Items until we navigate to the Private Page Items section

• Type: Regression Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: Master
• Fix Version/s: 7.1.X, Master
• Component/s: Frontend Infrastructure, Frontend Infrastructure > UI Taglibs
• Labels: None
• Fix Priority: 4
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/60776

Description
We get some weird UI appearing when we first Click on -> Page in Navigation Menu Admin. We cannot add any Pages in this UI. The workaround would be to navigate to the private pages section and then back to public pages.

Steps to Reproduce

1. Create a Public Page
2. Go to Navigation Menu Admin
3. Add A Page Item

Expected Result
Pages can be immediately selected

Actual Result
Private Pages must be navigated to first to fix the Public Pages UI

Reproduced on: Tomcat 9.0.6 + MariaDB 10.2
Portal master GIT ID: 360da1f75cd9a12c8f26679d8591b05c58423c9c