Memory leak in Multi-window scenario

[getrou]

Describe the bug

In a WinAppSDK multi-window scenario, the memory footprint increases even when windows are closed out.

Steps to reproduce the bug

1. Go to https://github.com/microsoft/WinUI-Samples and clone the repo.
2. Run MyApp.package.
3. Take a memory snapshot using VS's diagnostic tools.
4. Click the "Open Mini" button and then close out all the extra windows that were opened.
5. Take a second memory snapshot and compare.

Expected behavior

Memory footprint is the same before and after multi-window scenario.

Screenshots

NuGet package version

1.2.220727.1-experimental1

Packaging type

Packaged (MSIX)

Windows version

Windows 11 version 21H2 (22000)

IDE

Visual Studio 2022

Additional context

No response

[danielancines]

I've been making some tests here, and the problem appears to be in a Window object that still forever allocated, in my tests, even I closed New Window and check if it removed from App.Current.Windows collection, the object never will be collect by GC and I cannot find who is locking up on the object tree. Unfortunately I didn't find any workaround for this issue, do you guys have any idea?

[github-actions]

This issue is stale because it has been open 180 days with no activity. Remove stale label or comment or this will be closed in 5 days.

[JJBrychell]

There has been a lot of work on the shutdown process in 1.4 and we hope that that has addressed this issue. If this still continues to occur under 1.4, please feel free to reopen.

[rodirigos]

Still happening in dotnet8.