I've edited the RadTreeListView row template to add additional visuals that I need, but after the modifications an horizontal scrollbar appears and what seems to be an empty column header is added (image attached)
I've seen that the problem lies in the extra visuals I added to the row template, because when I remove the 2 colored borders the empty column header disappears.
Here you can find a sample project that reproduces the issue:
How can I prevent this issue and make the empty column header disapper ?
Thank you for your support.