Hello, Johnsa722.
Welcome to Apple Support Communities.
I understand that your notifications are only showing half of the message when they appear. I may be able to help you with this. Try adjusting your notifications and then revert the settings back. For example, from Banner type to Alerts type: Use Notifications on your Mac
If that doesn't help, try seeing if this occurs in a test user account and safe mode, this can help isolate it:
How to test an issue in another user account on your Mac
Use safe mode to isolate issues with your Mac
If it doesn't, occur in safe mode, restart and test again.
Keep me updated.