This issue #20556 did return in Joomla! 4

Steps to reproduce the issue

• Create menu consisting of URL type items and its subitems (that is important)
• Go to Modules -> New -> Menu
• Try to select in Base item any of the submenu URL type items you added in first step

Expected result

Able to select URL, Heading, Alias type menu item as Base item

Actual result

Menu item is inactive

System information (as much as possible)

Joomla! 4.2.4

Additional comments

Because of this you can't build a menu that will consist of parts of other menus cause you can't chose URL or Alias type of menu items.