Samsung
Enable or Disable Edge Lighting auf Samsung
Edge lighting is a notification style built into Samsung phones with a curved display. Instead of only showing a banner or a lock screen alert, the system draws a colored glow along the screen edge whenever a call, message, or app notification arrives. This works even when the screen is off, which is why the feature depends on a dedicated system toggle rather than the general notification settings.
If the glow no longer appears, the toggle for the effect has likely been turned off, or it was never activated after a reset. You control it in Settings ➔ Display ➔ Edge screen ➔ Edge lighting. Inside this menu, a single switch enables or disables the whole effect, and additional options let you pick the light style, color, duration, and transparency, plus which apps are allowed to trigger it.
Turning Edge lighting off can help save battery on devices that rely on an always-on curved panel, since less time is spent lighting the display for every incoming alert. If you only want fewer alerts rather than none, filtering the app list inside the same Edge screen menu is a better fix than disabling the feature entirely.
The option only appears on Galaxy models with a physically curved screen. On flat-display phones, the Edge screen entry is missing from Display settings because there is no edge to illuminate.