IgxTreeGrid multipleCascade selection + filtering scenario - sibling records get implicitly deselected

[ddaribo]

Description

The current behavior of the multipleCascade selection is such that the parent's selected state is determined based on the filtered-in children, in case of applied filtering conditions.
However, the result of performing the below listed steps might not quite be expected, as this behavior would cause non filtered-in sibling records' selections state to get implicitly changed.

• igniteui-angular version: any
• browser: any

Steps to reproduce

1. Open this demo from the Tree Grid Row Selection topic.
2. Choose 'Cascade' selection mode.
3. Select the first two child records of "Name: Johnathan Winchester"' - "Michael Burke" and "Thomas Anderson".
4. Filter the "Name" column by entering "bu" in the filter input - only the "Michael Burke" child remains.
5. Observe the Parent record checkbox state - it changes from indeterminate to checked since now all its visible children are selected.
6. The tree.selectedRows property could also be observed in the console - the currently selected records IDs are [1, 2, 3].
7. Now deselect the "Michael Burke" record -> both child and parent become deselected, because none of the filtered-in children of the parent are now selected.
8. Clear the filter.

Result

No selected records remain at this point, despite not having explicitly deselected the "Thomas Anderson" record.

Expected result

The non-filtered child record not to get deselected. It should become deselected only by explicitly deselecting it, or by deselecting its parent record, provided the child is within the currently filtered-in records.

Attachments

[Glopter]

Hello. Can anyone give a rough estimate of when work will start here?