Hello Timapple09,
Thank you for reaching out to Apple Support Communities.
If an app on your iPhone or iPad stops responding, closes unexpectedly, or won’t open
If an app on your iPhone or iPad doesn't work as expected, try this.
Close and reopen the app
Force the app to close. Then open the app to see if it works as expected.
Restart your device
Restart your iPhone or restart your iPad. Then open the app to see if it works as expected.
Check for updates
To see if updates are available for the app, open the App Store, tap your profile icon, then scroll down to see if updates are available. If updates aren't available for the app, update the software on your iPhone or iPad.
Delete the app, then redownload it
Delete the app. When you do this, you might lose data that was stored in the app. Then redownload the app. Then check to see if the problem with the app is fixed.*
*Per Delete built-in Apple apps from the Home Screen on your iOS 14 or later or iPadOS device or Apple Watch, the Messages app cannot be deleted so feel free to skip this step.
More details can be found here: If an app on your iPhone or iPad stops responding, closes unexpectedly, or won’t open
If the issue persists, can you provide a few more details? What is your exact iOS version? Did you load your current iPhone from a backup? Also, have you restarted your device since you first noticed this?
Cheers!