Calc losing chart data range on linked sheet


Libre Office version

I have a sheet1 that is linked to a web page and pulls the html table. based on this i have a chart on sheet2 .

The data on sheet1 is updated every few seconds. The column count changes and also row count. For chart data range i use a range more than what I expect the data to be.

When the column count goes down it is fine. but next when the column count/row count goes up the data range changes in the chart and keeps losing the range i had set.

every time the page updates i have to see if the chart data range is correct and correct it. i would like the data range to stay at what i set it to.

Not sure is this is a bug or i am doing something wrong.
Please advise.
Thanks for your time!