iPhone 11 - Creating Screen Saver after each call

Recently, my iPhone 11 has been auto generating screen savers (of sorts) after each call - whether the call is inbound or outbound. These call screen savers over ride my wallpaper and prevent me from seeing any notifications on my screen. I've tried shutting down the phone but this screen saver is preventing me from doing it. Granted, I can let the battery die and recharge to reboot that way, but wondering why this is happening and how to prevent it.