IgxTreeGrid: Wrong parent record when adding new child row

[ddaribo]

Description

When a new child record is added, the parent record is wrong. The following precondtions should be met to reproduce this:

1. all records must have been previously collapsed - either manually or by invoking the tree grid's collapseAll() method.
2. the grid should be scrollable after expanding the records
3. the grid needs to be scrolled a bit after some records are expanded

• igniteui-angular version: all supported
• browser: any

Steps to reproduce

1. Open this demo
2. Collapse all records
3. Now expand "Victoria Lincoln" and "Yang Wang" so that the grid gets scrollable again.
4. Scroll the grid a bit.
5. Attempt to add a child row to "Yang Wang" through the action strip. As a result the target record is collapsed.
6. Observe where the add row UI is rendered. When editing is finished, the new record is added as a child to the previous record, and not the target one.

Result

Add row UI is not in the proper place and the new record is added as child to the record above.

Expected result

Have the add row UI in the correct place and for the new record to be added as child to the target record.

Attachments

Attach a sample if available, and screenshots, if applicable.