Original topic:
Screen randomly dims and locks while actively being used after One UI 8.5
(Post creation time:
09-14-2026 06:20 PM
)
685 Views
L
Lilibug
Constellation
Galaxy S24 Ultra— Screen randomly dims and locks despite active user input after One UI 8.5
Since updating to One UI 8.5 on September 10, my S24 Ultra has randomly dimmed and locked the screen while I was actively using it. My screen timeout is set to 10 minutes, adaptive brightness is off, and I haven't changed any relevant settings or installed any new apps.
This has happened three times so far. The most recent two happened within several minutes of each other while I was actively typing. The screen suddenly dims and then locks, but the phone itself is still functioning normally: the Always On Display remains visible, notifications still come through, and pressing the power button wakes the phone normally. The phone also doesn't become warmer.
I've also noticed other odd behavior since the update, including the notification panel not always responding when I try to pull it down and unusually fast battery drain.
Has anyone else experienced these issues since updating to One UI 8.5, particularly the screen dimming and locking despite active use?
Selected Answer
SamsungModerator1
Community Manager
09-14-2026 06:40 PM
in
Hello, @Lilibug
Thank you for reaching out to the Community about your S24 Ultra screen randomly dimming and locking while typing after the One UI 8.5 update. We want to help resolve this alongside the notification panel lag and battery drain you mentioned. Here are a few quick troubleshooting steps to help isolate the software glitch:
Force-Refresh Display & Timeout Registers: Sometimes system parameters get stuck immediately following a major firmware update. Navigate to Settings > Display > Screen timeout. Temporarily change it to 1 minute, restart your phone, and then change it back to your preferred 10 minutes.
Go to Settings > Advanced features > Motions and gestures and toggle Keep screen on while viewing on and off to reset the front-facing camera's presence detection sensors.
Test in Safe Mode: To rule out a third-party app conflicting with the new One UI 8.5 display or touch framework, you should temporarily isolate your core system. Press and hold the Side button and Volume down button simultaneously to open the Power menu. Touch and hold the Power off icon until the Safe Mode prompt appears . Tap Safe mode to restart your device. Test your typing while the phone is in this state.
For more detailed instructions on how to use or exit this diagnostic state, check out the official Samsung Safe Mode Guide. If the dimming completely stops, an unoptimized background app is likely hijacking your input focus.
Give these steps a try and lets us know the results so we can assist further if needed!