bug(drag'n'drop): List order changes despite cdkDropListSortingDisabled

[daloo]

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

cdkDropListSortingDisabled does not prevent reordering when dragging an item back to its original list

Reproduction

StackBlitz link: https://stackblitz.com/edit/stackblitz-starters-zdflpxgr
Steps to reproduce:

1. Drag the last task ("Cleaning") over any day element without dropping it.
2. Drag it back to the task list.

Expected Behavior

I expect the order of the list to be not modified.

Actual Behavior

The "Cleaning" task is no longer the last item and appears in second position.

Environment

• Angular: 21.1.0
• CDK/Material:21.2.2
• Browser(s):Chrome
• Operating System (e.g. Windows, macOS, Ubuntu):linux x64