Using Tree Grid with Grid Widget - Same Childs for every Parent Row

Hello.

I'm trying to use the Tree Grid, within the Grid Widget.

I have created two Infotables. One with Parent Data and another for Child Data.

Parent Data Output:

Child Data Output:

Bindings:

Data: -> Parent Data Table

ChildData: -> Child Data Table

IDFieldName: UID

ParentIDFieldName: ParentUID
HasChildrenFieldName: hasChildren

Result:
With the following approach mentioned above, I have 3 rows as output.

Row 1 and 2 can be expanded to show the children, but not row 3 as expected.

However, if I expand row 1, I have all 3 Child Data Rows in there.

If I expand row 2, I also have all 3 Child Data Rows in there.

I don't know what to change anymore.
Can someone help?

Best Regards.