
There will be no need, or shouldn't to reinstall anything you have done but that screen showed up after each update. Select Messenger Home, tap 'Home Screen', and change back to your preferred Home Screen experience. And where it shows to set default make sure both are default and you should be good to go. You can return to your default home screen by going to Settings - System - Apps. If not yet, then swipe down, look for Gear Icon, click it, go down to apps, tap it, then go looking for messenger in the list. Then if your home screen is back to normal you have done it. Ignore any warnings about it is or needs to be on your phone (mine didn't but unwanted apps will try to convince you they are needed or else the whole system is going to crash, blow up, or whatever - as I said just ignore) and then when you see uninstall. On there you should see under the icon, "Uninstall". On Android you can select Signal as your default messenger, using Signal and SMS side by side, to deliver a similar user experience. It will open the page in the app store/google play/or whatever you prefer to call it. One again swipe your finger up till you get to the bottom and " App Details in Store". Find Messenger and Messenger Home in that list.

Now tap on Apps and now you should see a long list hopefully in alphabetical order. Now scroll up (meaning you want to see what is below) and using the Verizon Samsung 20+5G default settings look for Apps (about 18th or 19th item on list) and it should show underneath it, "Default apps. If you tapped the right one it will say Settings. At the home screen swipe down then click on that little gear icon in the near upper right.
