Hey dcaldarone,
We understand your notifications aren't working for the Messages app on your iPhone. We'll be happy to help.
To start, do you still see the badge app notifications on the icon? If you swipe down from top of iPhone to view Notification Center, do your notifications appear there? If neither are showing up, you might also have Do Not Disturb enabled or another Focus. To check, swipe down from top-right corner to see if you have a Focus enabled. For more info on checking this, take a look at: Use Focus on your iPhone or iPad - Apple Support
We look forward to hearing what you find out and whether or not this is related to a Focus or not.
Take care!