bug(aria): Touch scrolling starting on a listbox option triggers unintended selection

[Mikastark]

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

When using ngListbox on touch devices inside a scrollable container, starting a scroll gesture on top of an option immediately selects that option.

This makes it difficult for users to scroll through the list if their finger initially touches an option. Instead of simply scrolling, the option is selected even though the user’s intention was to scroll.

This behavior results in frequent accidental selections and makes the component harder to use on mobile devices when the listbox content is scrollable.

Reproduction

Steps to reproduce:

1. Go to https://angular.dev/guide/aria/listbox with a smartphone (updated iPhone 16e in my case)
2. initiate a scroll gesture on the first example and see the option your finger touch become selected

Expected Behavior

Selection should happen on pointer up not pointer down

Actual Behavior

Unwanted selection that can trigger behaviors like HTTP requests

Environment

• Angular: 21.2.2
• CDK/Material: 21.2.2
• Browser(s): Safari iOS
• Operating System (e.g. Windows, macOS, Ubuntu): iOS 26.2.1