Check both app and device settings.
In Settings, choose notifications, channels and quiet hours. The operating system must also allow the selected channel. Denying a device permission does not prevent you from opening your agenda or completing a task.
Keep lock-screen content private.
Native push messages use minimal content and open the relevant item after access is checked. Email detail follows your privacy preference and channel settings. A notification does not grant someone access to the linked meeting or note.
When a reminder does not arrive.
Check the saved time zone, quiet hours, channel preference and current device registration. A completed, deleted or rescheduled item should not send its old reminder. A temporary delivery pause can delay work; expired reminders are suppressed when delivery resumes. Actual push delivery still requires configured services and supported device testing.