Hello thompson615,
For odd behaviors that may crop up, some steps that can help would include trying to force quit the Messages app, and restart the device.
This page will have the steps for forcing the app to close, if needed: Close an app on your iPhone or iPod touch - Apple Support
iPhone X and later
1. From the Home Screen, swipe up from the bottom of the screen and pause in the middle of the screen.
2. Swipe right or left to find the app that you want to close.
3. Swipe up on the app's preview to close the app.
This one can assist with restarting the iPhone: Restart your iPhone - Apple Support
You may also double-check in Settings > General > About to see if it notes that iOS 16.3 is the installed version to confirm it's using the latest available version.
Cheers.