Hello Babydoll8587, welcome to the Samsung Community! I understand your frustrations with your notifications not showing on your lock screen. Please note: If you have a lock screen set up, you will need to enter your credentials to view the notification. To access lock screen notification settings: Open Settings, Swipe to Notifications, tap lock screen Notifications, tap the Switch at the top to turn on lock screen notifications. From there you can customize the available settings to your liking: Notification style (Choose how new Notifications show in the status bar), Hide or Show Content, Show Alerting Notifications only (the most important notifications that require immediate attention will be visible on your lock screen).
You can clear the cache to the messaging app as well as your device cache partition: with your device powered off hold the volume up and power button together at same time, once the Samsung Logo appears then release the power button, select clear cache partition and reboot your device as normal.
Please let me know if you require further assistance.
