Submenu opened with hover does not close by Escape key when another menu item has focus

Problem/Motivation

In 📌 Ensure keyboard navigation works with the drawer Active , the Submenu spec says for Escape:

• Closes submenu.

For me in the "desktop" version, when a submenu is opened by hover and a second menubar (aka, "parent") item has focus, Escape does not close the submenu.

WCAG success criteria

• 2.1.1: Keyboard (Level A)
• Possibly also a violation of the Dismissible criterion of SC 1.4.13 Content on Hover or Focus:
  

  A mechanism is available to dismiss the additional content without moving pointer hover or keyboard focus, unless the additional content communicates an input error or does not obscure or replace other content

Related technique

Steps to reproduce

1. Enable the Navigation module.
2. Log in as admin.
3. Tab to an item in the Navigation menu bar that has a submenu.
4. With the focus still on the item above, hover the cursor over a second parent menu item so that the submenu of this second item opens.
5. Press Escape.

Pressing Escape closes the submenu that is opened by hover.

Pressing Escape does not close the submenu that is opened by hover.

In the attached video, both the Shortcuts submenu and the Content submenu are opened by hover.

Escape did close the Shortcuts submenu as expected. However, I am pressing Escape while the Content submenu is open, and it's not closing.

Proposed resolution

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet