Pin issues

[nasterhe]

The follow is my code.

public override IRootDock CreateLayout()
{
    ProjectTreeViewModel = new ProjectTreeViewModel()
    {
        Id = "ProjectTreeView",
        Title = "None",
        CanClose = false,
        CanFloat = false,
        CanPin = true,
        ProjectDockFactory = this
    };
    var prj = new ProportionalDock
    {
        Proportion = 0.15,
        CanPin = true,
        VisibleDockables = CreateList<IDockable>
   (
       new ToolDock
       {
           VisibleDockables = CreateList<IDockable>
           (
               ProjectTreeViewModel
           ),
       }
   )
    };
    TableHelperViewModel = new TableHelperViewModel()
    {
        Id = "TableHelperView",
        CanClose = false,
        CanFloat = false,
        CanPin = false,
        ProjectDockFactory = this
    };
    var table = new ProportionalDock
    {
        //Proportion = 0.7,
        VisibleDockables = CreateList<IDockable>
   (
       new ToolDock
       {
           VisibleDockables = CreateList<IDockable>
           (
               TableHelperViewModel
           ),
           GripMode = GripMode.Hidden
       }

   )
    };
    PropertyControlViewModel = new PropertyControlViewModel()
    {
        Id = "PropertyControlView",
        Title = "ControlInfo",
        CanClose = false,
        CanFloat = false,
        CanPin = true,
        ProjectDockFactory = this
    };
    var prop = new ProportionalDock
    {
        Proportion = 0.15,
        CanPin = true,
        VisibleDockables = CreateList<IDockable>
   (
       new ToolDock
       {
           VisibleDockables = CreateList<IDockable>
           (
               PropertyControlViewModel
           ),
       }

   )
    };
    var windowLayout = CreateRootDock();
    var windowLayoutContent = new ProportionalDock
    {
        Orientation = Orientation.Horizontal,
        IsCollapsable = false,
        ActiveDockable = prj,
        VisibleDockables = CreateList<IDockable>
        (
            prj,
            new ProportionalDockSplitter(),
            table,
            new ProportionalDockSplitter(),
            prop
        )
    };
    windowLayout.IsCollapsable = false;
    windowLayout.VisibleDockables = CreateList<IDockable>(windowLayoutContent);
    windowLayout.ActiveDockable = windowLayoutContent;

    var rootDock = CreateRootDock();

    rootDock.IsCollapsable = false;
    rootDock.VisibleDockables = CreateList<IDockable>(windowLayout);
    rootDock.ActiveDockable = windowLayout;
    rootDock.DefaultDockable = windowLayout;
    _rootDock = rootDock;

    return rootDock;
}

When I click the Pin button on the left, the panel on the left docks to the left, but a narrow bar appears on the right. When I click the Pin button on the right, the panel on the right is docked to the left instead of on the right, and the white space on the right becomes wider.
Please tell me where I made a mistake.Thanks.

[nasterhe]

The issue persists with the latest version 11.2.7.