Rowspan in treegrid

Hi our application was using older versions of dhtmlx.
We rowspan some cells in rows in tree grid.
After upgrading to latest version(3.6), its not spanning.
In some post I saw its not supported. Is that correct?

I am loading the grid using xml.

If there is a way, please let me know.

The rowspan may work in treegrid, but your treegrid structure may get broken in case of rowspanning the rows that are on the different levels. Unfortunately this limitation cannot be eliminated so officially the rowspan is not supported in the treegrid due to it’s instability