Example: https://buildingdetails.com/
This site does not have any custom JS or CSS that impacts the menu functionality.
Desktop:
1. The submenu is displayed immediately upon receiving focus, which makes it painful for keyboard users trying to get to other top-level menu items.
2. Esc key does not close the submenu.
Mobile:
3. Esc key does not close the menu when toggled open via the keyboard.
This site is running 3.2.1 and 2.2.0. I had read that 2.2.0 would fix a number of keyboard accessibility issues, but these issues persist.