For the past couple of nights, both of my kids brand new S5s displays stay on after becoming fully charged. Any ideas? I checked display timeout, both at 1 minute.
Check and see if developer options is enabled. If it is, check to see if stay awake while charging us checked.
When the phone gets to 100% a notification wakes the screen up to let you know that it's fully charged. And if stay awake while charging is enabled, it will keep the screen on once that notification wakes it up.