Screen Time Out

The behavior is caused by a different timeout than the one already changed. Windows has several separate timers:

1. Screen off / sleep timeout (what was set to 30 minutes)
2. Lock screen / slideshow / screen saver timeouts (which can still be much shorter)
3. Energy recommendations that may have shortened defaults

On Windows 11, verify and adjust these:

1. Check screen and sleep timeouts
   1. Select Start > Settings > System > Power & battery.
   2. Select Screen, sleep, & hibernate timeouts.
   3. Under both On battery and When plugged in, set:
      • Turn my screen off after to the desired value (for example, 30 minutes).
      • Make my device sleep after to the desired value (equal to or longer than the screen-off time).
2. Check Energy recommendations (they can override to very short values)
   1. In Settings, go to System > Power & battery > Energy recommendations.
   2. Review and adjust:
      • Turn off my screen after 3 (or 10) minutes – if this is applied, it will shorten the screen timeout regardless of the 30‑minute setting. Turn this off or change it back to the preferred value.
      • Any other recommendations that change brightness or sleep behavior if they are not desired.
3. Check lock screen slideshow / pictures The pictures appearing after a short idle period are typically the lock screen slideshow or a screen saver, which uses its own timeout. Increase or disable that timeout in Personalization > Lock screen or Screen saver settings so it does not activate after ~30 seconds.

Once the Energy recommendation for “Turn off my screen after 3 (or 10) minutes” and any short lock screen/screen saver timeout are disabled or extended, the screen will respect the 30‑minute idle setting instead of blanking and showing pictures almost immediately.

References:

• Learn more about energy recommendations
• Power settings in Windows 11
• Display idle timeout
• Sleep idle timeout
• Policy CSP - Power