Are you having problems with the new iOS 13 install? I am running the latest version iOS 13.1.2, but I still have had a few issues including the Messages App. My wife has had some issues as well. I know you have heard this many time with your Mac or PC, but one way to fix some of these problems is to Restart your iOS device! Here is how that is done on the iPhone 11.
iPhone 11 Restart
If you have a different iPhone than one of the newer iPhones, then go to this Apple Support Page to know how to Restart your iPhone. For the iPhone X or later do the following from your Home Screen:
Hold down one of the Volume Up/Down buttons and the right-side button on the iPhone until you see this screen:
Just slide the “slide to power off” and the iPhone will shut completely down. Wait a few seconds and then push the right-side power button to start the iPhone. You have to hold this button down for a bit until you see the Apple Logo. IOS will come to the screen for you to enter your login code, no Face ID on an initial startup in iOS 13. That is all there is to it.
I was having trouble with the Messages App showing all the controls. This issue was fixed after a Restart. My wife was having difficulty texting certain people. This issue was partially fixed after a Restart.
It is not a cure-all, but a Restart of your iOS 13 Device may solve some problems you are having. Hopefully, Apple will fix these issues in future iOS 13 updates.