TreeView scrolling is not working when virtualization is not enabled.

[Korjam]

Describe the bug

TreeView scrolling is not working when virtualization is not enabled.

To Reproduce

1. Create a TreeView containing at least one item with many child items
2. Expand the the item with many childs
3. Reduce the window size until the scroll control appears
4. Scroll down.

Following this steps it scroll the entire list of childs from the item 1 and goes directly to the second item.

<TreeView>
  <TreeViewItem Header="Item 1">
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
    <TreeViewItem Header="Child" />
  </TreeViewItem>
  <TreeViewItem  Header="Item 2" />
</TreeView>

Expected behavior

An stepped scroll where you can see all the child items.

A workarround for this issue is to enable virtualization in TreeView:

VirtualizingPanel.IsVirtualizing="True"

Screenshots

OS version

Windows 11

.NET version

.NET 7

WPF-UI NuGet version

• 3.0.0-preview.1
• 2.0.3

Additional context

No response