NotificationToast | Android Notification Toast without any device | Notification library

I am trying to create a Toast Notification in WPF, my problem is that if I, in this case, delete something from the database too quickly, the current notification just gets upgraded with the new text instead of creating a new instance of the class, so I can see two notifications.

The notification becomes a child of a StackPanelfrom the MainWindow, that way it always has the same position. That is why I clear the children at the beginning.

The class works, it's just that I cannot manage to have more than one notification at a time.

What am I missing? Sorry, I am quite a beginner and I tried to do this by myself.

This is my class code

I have build an app that is supposed to show Toast Notifications on Windows 10, every time a FileSystemWatcher detects a change. I am using the Microsoft.Toolkit.Uwp.Notifications and Windows.UI.Notifications namespaces. When running the code in VS2019 with the debugger enabled, it works flawlessly, but after installing the application using a self-written WiX installer, I get an error message after which the app closes.

The error message is pretty generic, and I am out of clues as to where to look:

Failed to show Notification for [FileSystemWatcher Name].
Element Not Found. (Exception from HRESULT: 0x80070490)
at Windows.UI.Notifications.ToastNotificationManager.CreateToastNotifier()
at ...
at .. rest of callstack is from the app, pointing towards the method with CreateToast

The class that is responsible for creating and showing the toasts

I am trying to set OnClickListener on an Android button in Kotlin file. Unlike java file, where I can declare button variable at the class level and initialize it in onCreate method and assign ClickListener at the same time as: