App switcher not working

I have an iPhoneX. A few days ago the App Switching function stopped working. I can still swipe up to activate the function but no longer swipe left or right to select the app I want closed. Is this the result of a software update?

Switch apps on iPhone X and iPad

1. Swipe up from the bottom to the middle of your screen and hold until you see the App Switcher.
2. Swipe left or right to find the app that you want to use.
3. Tap the app.

Switch apps on your iPhone, iPad, or iPod touch - Apple Support