MainActivity base.OnCreate() crush

Question

The app is running on MAUI. When the app is in the background, the movement differs between the task being turned off and the state where it is not. If the task is in the background and the task is turned off, when the push notification comes, when the notification is pressed, it will transition to the app, but if the task is not turned off in the background, it will crash before transitioning to the app when the notification is pressed. The error is Handler is not set on Element, and the error is in the base. It's happening in OnCreate(bundle). The cause is unknown. Help me.