Gantt Chart – Display category adjustments

Hi guys,

I about to buy the license for 3 users, but I need to know first: How can I freeze the columns from display category in Gantt Chart???

Everytime i go out of the page in Gantt Chart xViz and go back again, the size of the columns in “display category” change the way i had configured the size. Why!? And it´s not in “auto” mode

P.S.: ‘Display Categories’ not appears for me (even in previous version of Power BI)

Thanks!