Does the night clock have a screensaver against burn-ins on OLED displays?

Settings / Apps / Special App Access / Autostart or Settings / More settings / Applications / Autostart or Manager / App […]

If your device has a LCD display than you will not get a complete dark screen even if nothing is displayed on […]

Phone Assistant / Manager / Battery / Eco. ModeTurn off Eco Mode Phone Assistant / Manager / Battery / Optimized ModeDisable optimized mode […]

(Maybe not all changes are required. Try for yourself and report back please) Settings / Smart Manager / Auto-start Turn off Automatically […]