Samsung Galaxy S26+ screen or touch input is not working correctly

A Galaxy S26+ with a 6.7 inch QHD+ screen running at 120 Hz should respond instantly, so a screen that lags, ignores touches or taps by itself is worth ruling out in a few steps. The glass is Gorilla Glass Victus 2 and the phone is IP68 rated, so water on the screen is a likely cause of ghost touches, and the screen should be dried completely. Remove any protector, because a poor film affects the edge touch and the ultrasonic fingerprint sensor, and check Touch sensitivity under Settings, Display. Owners of One UI 8.5 phones describe random freezing as well, which looks like a touch fault when the whole phone is stuck;

check whether the status bar clock stops, which means the phone is frozen and not the screen. Restart and test in Safe mode. A refresh rate set to Adaptive can feel laggy if the system is busy, so try Standard for a test. A line or a dead zone that remains in Safe mode is a hardware fault on a phone that is still in warranty. Edge panels and gesture navigation can also be mistaken for a touch fault: swipes from the screen edge trigger the back gesture or the Edge panel, so a phone that seems to ignore touches near the sides may be responding to a gesture. Check Settings, Display, Navigation bar, and Edge panels to see what is enabled.