A. Check your notification settings in the iPhone settings. Go to Settings > Notifications > TeleGuard and ensure that 'Allow Notifications' is turned on. Also, check if 'Show in History' and 'Show on Lock Screen' are enabled.

B. Make sure that Do Not Disturb mode is not enabled. Swipe down from the top right corner of your screen to access Control Center and check if the crescent moon icon is highlighted. If it is, tap it to disable.