Tree Table issue. Not displaying the children data

Hello All. I am trying to use the tree table to show a product structure and what I am seeing is an stability issue. I had it working for some time and there for some reason it does not work anymore.

I already tried different versions of the core-ui (1.1 and 2.0) but it seems It does not matter

BTW, the widget config was straight fwd:

Here is a screenshot of the data:

And here's the tree:

Here's the Issue in the Browser Console: