I built up a toast notification with reference to the following sites.
However, when executed as an administrator, can not access the parent program from the toast. It starts up as a new program.
It can be executed with no problems with ordinary users.
The toast implementation is here.
[DesktopNotificationManagerCompat.cs file from GitHub] https://raw.githubusercontent.com/WindowsNotifications/desktop-toasts/master/CS/DesktopToastsApp/DesktopNotificationManagerCompat.cs
I am running as Non-Desktop Bridge.