Question

How to make a non visible Node in the grid visible?

TreeNode.Selected := true;
TreeNode.Visible := true;
phGant.Grid.FocusedCell := phGant.Grid.Cell[ 0, TreeNode.AxisContentItem.ItemIndex ];
phGant.Grid.FocusedCell.Selected := true;
phGant.Grid.MakeSureFocusedIsVisible;

This Code selects the Node but it does not make it visible.

Answer

The code should make a Node that is scrolled out of view visible (by scrolling it into view)...
Maybe this node is a non Expanded parent?

TreeNode.ParentNode.Expanded=true should fix that (unless that node also is in collapsed parent)

If this does not fix the problem you better send us a repeating sample so that we may debug and see what fails.