bug(aria/menu): activating the menu doesn't move focus to menu items

[artaommahe]

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

No response

Description

Keyboard focus stays on the menu trigger when opening the menu. Happens only for the main menu list, works fine for submenus.

Reproduction

StackBlitz link: https://angular.dev/guide/aria/menu
Steps to reproduce:

1. focus the first example menu trigger with a keyboard
2. press Enter/Space/ArrowDown/ArrowUp
3. see menu open but focus still stays on the trigger
4. press the same key again
5. now focus finally moves to the expected menu item (last one on ArrowUp pressed)

Expected Behavior

On menu open focus should immediately move to the first/last menu item.

Actual Behavior

On menu open focus stays on the menu trigger

Environment

• Angular: 22.1.4
• CDK/Material: 22.1.4
• Browser(s): Chrome 151.0.7922.174
• Operating System (e.g. Windows, macOS, Ubuntu): macOS