WinUI 3 - ListBox drag and drop causes a crash

Describe the bug A ListBox is used to display controls that can be dragged and dropped to rearrange the controls. To indicate the drop position the appropriate border of the control where the dragged item will be dropped is changed. Dragging and dropping a different control in a different position a few times will result in a crash with the error message posted below.

Steps to reproduce the bug Steps to reproduce the behavior:

1. Download the repository here that contains a repro build.
2. Ensure that the ListViewDragDropIssue (Package) is set as the startup project.
3. Press F5 to run the project.
4. Drag and drop a control from one position into another one a few time.
5. After anywhere between 2 and 5 drag and drop operations a crash will occur.

Expected behavior Application should not crash and allow the user to continue dragging controls for as long as they wish.

Screenshots

Version Info WinUI 3 Windows App SDK 0.8.1 Packaged Win32 desktop application Windows 11 Pro build 22000.100

NuGet package version: Microsoft.ProjectReunion 0.8.1 Microsoft.ProjectReunion.Foundation 0.8.1 Microsoft.ProjectReunion.WinUI 0.8.1 Microsoft.Windows.CsWinRT 1.3.3 PropertyChanged.Fody 3.4.0

Windows app type:

UWP	Win32
	Yes

Windows version	Saw the problem?
Insider Build (22000.100)	Yes
October 2020 Update (19042)
May 2020 Update (19041)
November 2019 Update (18363)
May 2019 Update (18362)
October 2018 Update (17763)
April 2018 Update (17134)
Fall Creators Update (16299)
Creators Update (15063)

Device form factor	Saw the problem?
Desktop	Yes
Xbox
Surface Hub
IoT

Additional context Does not appear to happen if logic to change the borders ListPage.xaml.cs line 57 - 69 are commented out.

[StephenLPeters]

Awesome!

The listbox issue is very unlikely to get looked at any time soon as we no longer want/recommend people use the control.

[DeadlyEmbrace]

Just gave it a try and it fulfills my needs perfectly. Thanks for pointing it out 😄