useTable creates extra header object element for fourth nested column

[acebelaro]

Hello.

I am using react-table useTable API to create header array objects and I am trying to create a table with a header like

Here is the the JS data
SampleData.txt

However, the actual output is

Current netlify upload https://romantic-pasteur-123a68.netlify.app/

[Initial Investigation]

I added console logging of the elements of the header output of 'useTable' API of react-table.

My guess is shown in the image.

I am relatively new in react-js so I apologize if my investigation is incorrect.

Thank you.

PS.
This is my first time posting here. I apologize in advance in case of insufficient details.