How to Fix Mac Sleeps While Watching Movies After macOS Update (Stop Sleep During Video Playback)

Many Mac users notice a strange problem after updating macOS. The Mac goes to sleep while watching movies, streaming shows, or playing videos, even when the display timeout is set correctly. This usually happens because macOS changes power, battery, or lock screen settings during updates.

This guide explains how to stop your Mac from sleeping during video playback without setting the display timeout to Never.

Why Mac Sleeps While Watching Videos After Update

After a macOS update, the system may reset battery, display, or App Nap settings. When this happens, macOS may think the computer is idle even while a video is playing.

Common causes include:

• Low Power Mode enabled
• Lock Screen timeout changed
• App Nap active
• Screen saver settings reset
• Power management settings modified

Fixing these settings usually solves the problem.

Method 1 — Change Lock Screen Display Timeout

macOS may turn off the display too quickly after the update.

Steps:

1. Open System Settings
2. Click Lock Screen
3. Find Turn display off on battery when inactive
4. Set it to 5 minutes or more
5. Do the same for Power Adapter

Do not set it to Never unless nothing else works.

Method 2 — Disable Low Power Mode

Low Power Mode can force the Mac to sleep even during video playback.

Steps:

1. Open System Settings
2. Click Battery
3. Turn OFF Low Power Mode for battery
4. Turn OFF Low Power Mode for power adapter
5. Restart the Mac

Many users report this fix works after macOS updates.

Method 3 — Disable App Nap for Browser or Video Player

macOS may pause apps in the background to save power. This feature can stop video playback activity detection.

Steps:

1. Open Finder
2. Go to Applications
3. Right-click Safari, Chrome, or VLC
4. Click Get Info
5. Enable Prevent App Nap

Repeat for the app you use to watch videos.

Method 4 — Check Screen Saver Settings

Updates sometimes change screen saver timing.

Steps:

1. Open System Settings
2. Click Screen Saver
3. Set Start After to a longer time
4. Go to Lock Screen
5. Increase Require password after sleep time

Short timers can cause sleep during movies.

Method 5 — Reset macOS Power Management (Best Fix)

If the problem started after an update, resetting power settings often fixes it.

Steps:

1. Open Terminal
2. Type:

sudo pmset -a disablesleep 0

3. Press Enter
4. Enter your password
5. Restart the Mac

This restores normal sleep behavior.

Method 6 — Test With Another Browser or Player

Sometimes the issue comes from the app, not macOS.

Try:

• Safari
• Chrome
• VLC
• Netflix / Prime / YouTube in another browser

If the Mac does not sleep in another app, update the original app.

In most cases, Mac sleeping during movies happens because Low Power Mode, Lock Screen timeout, or App Nap changes after a macOS update. Adjusting these settings restores normal playback behavior without disabling sleep completely.

After fixing the settings, the Mac should stay awake while watching shows, movies, or streaming videos.