Some Galaxy S9 and S9 Plus units have large dead zones on the touchscreen

Ryne Hager, Android Police:

The touchscreen on your phone is the primary way you interact with it, so it absolutely needs to work. That makes problems like so-called “dead zones” or ignored/unregistered inputs among the most annoying out there. Based on reports, many are running into those types of touchscreen input problems with Samsung’s Galaxy S9+.

It’s tough to tell precisely how common the problem might be. Few users are as apt to report issues as Pixel-purchasers, so we can’t quite compare things against our coverage for Google’s hardware. But from what we have seen in places like Reddit, it’s reasonably widespread.

Yikes.