Select-all checkbox triggers loading of child nodes when checkChildren is "false"

[zstoyanova9]

Description

When the showSelectAll property of the TreeList CheckboxColumnComponent is enabled and the checkChildren property is set to "false", checking the select-all checkbox triggers loading of child nodes.

Steps To Reproduce

1. Open the following StackBlitz example - https://stackblitz.com/edit/angular-e2ai4pjx-hcb2vjba
2. Check the select-all checkbox of the TreeList and see how the fetchChildren function is triggered for all nodes.

Screenshots or video

Screen.Recording.2025-07-29.at.14.33.21.mov

Actual Behavior

The loading of child nodes is triggered when clicking the select-all checkbox of the TreeList, despite checkChildren being set to "false".

Expected Behavior

As noted in our documentation, the loading of child nodes should not be triggered when using the select-all feature with checkChildren set to "false".