We are seeing stability issues over time with UE5 projects on Android. Repeated screen orientation changes throughout the day on our test devices, while a UE-based game is backgrounded, will eventually slow down Android’s system_server. As this progresses, system services it manages, especially SystemUI, will report a VK_ERROR_DEVICE_LOST.
From there, the UE game will either restart or the device will trigger a full system restart.
We enabled GPU debug layers and did not find anything obviously wrong. Disabling OpenGL shader support seems to extend both system stability and UE stability (the game wakes from background correctly), but the device becomes extremely sluggish, especially during text input, and eventually forces a restart.
I. Environment tested:
II. Reproduction steps:
- Launch a UE Android game from the editor or sideloaded.
- Background the UE game.
- Open Chrome or any app that reacts to orientation changes.
- Rapidly switch orientations. Scripting is easiest. We used the following (sluggishness and instability start around 250 orientation flips):
adb shell wm user-rotation lock <0..3>
- Type text in any field/app, then switch back to the backgrounded UE game.
Expected result: Either the UE game restarts or the device restarts.
III. Baseline tests:
- Minimal native C++ Vulkan test (Khronos cube): no issues.
- Another major commercial engine used in one of our shipped titles: no issues.
We’re not sure if this is related to the issue noted here:
https://forums.unrealengine.com/t/anr-onresume-and-surfacedestroyed/2668188
But in internal tests, we’re able to reproduce this consistently however in both UE 5.3 and UE 5.6.
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Hi Rune,
Are you able to confirm whether the behaviour is specific to the device config listed or if the issue has been seen on other devices/GPU families/Android versions?
Best regards.
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Hi Rune,
This is currently being investigated internally by the development team. However, with winter break around the corner here at Epic, I suspect we won’t have much to report till early 2026. If this is immediately pressing, please advise and we can try to see if there’s a way to expedite.
Best regards.
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Hi Rune,
Testing and investigation is still ongoing. Keep you posted once we have more details.
Thanks!
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Hi Rune,
Our QA has run some tests on an Google Pixel 9 running Android 16, and did not observe the issue in any capacity. They were rotating for at least 400 times on the Chrome app foregrounded after launching and backgrounding the UE application.
for (( repeats = 0; repeats <= 100; repeats++ ))
do
for (( rot = 0; rot <= 3; rot++ ))
do
adb shell wm user-rotation lock $rot
sleep 0.4
done
done
Tested on:
- //UE5/Release-5.6 CL 48387509 Perforce
- Lyra - Launch On
- RenderingValidation - Launch on and Package
- QAGame - Launch On
- //UE5/Release-5.6 CL 44394996 Binary
- First Person Shooter Template (Arena Shooter) - Launch On and Package
- //UE5/Release-5.7 CL 49658320 Perforce
- RenderingValidation - Launch On and Package - Also did not observe though, was tested with less rotations, not much more than 250
I’ll confirm Build/Kernel with them in case there’s an update difference here.
Best regards.
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Hi Rune,
Yes, that’s what I instructed QA to do in their tests as per your original repro steps. Launch UE game, background it, launch Chrome and run the rotations through automation while Chrome is foregrounded. I’ll circle back once they’ve confirmed Kernel/Build to make sure we are in sync. It would also be interesting to know if the issue reproduces on your end with factory reset devices.
Best regards.
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Hi Rune,
I just confirmed with QA that in all cases, no slowdown was observed and additionally that the UE app resumed sucessfully after being backgrounded. Here is the Pixel 9 Kernel/Build information.
[Image Removed]Best regards.
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Hi Stéphane,
We’ve seen the behaviour so far in Pixels 8 & 9 - we’ll try to check with other devices (depending on availability).
What does Epic have in terms of test devices for repro? Will be good to understand if you can repro on your end as well.
Thanks,
Rune
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Additional test results from our QA team as promised:
Device - Pixel 7a:
- Android 14/build AP2A.240805.005 = no repro
- Android 15/build BP1A.250305.019 = no repro
- Android 16/build BP3A.251005.004.B2 = no repro
So it appears to affect more modern hardware on Android 16. Behavior seems isolated with UE builds on Android 16 (as per original ticket).
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Hi Stéphane - just bumping for any updates on this? 
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Thanks [Content removed]
Really appreciate the update and glad the team’s already looking into it.
We’re also going on our global end of year break so its not immediately pressing.
Thanks!
Rune
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Happy New Year!
I know it’s early - but any chance there’s some progress Epic can share on this?
Let us know if you need any more info from our end!
Cheers,
Rune
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Thanks Stephane! We’re keen to have some resolution or if there’s any workaround we can do at this time, it’d be great as it has impact in our QA processes and velocity.
Thanks,
Rune.
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That’s interesting - thanks for the update.
Can they try minimizing UE so that’s in the background and try doing the screen orientation changes from say Chrome? We notice the issue in particular when you background a UE game.
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oh sorry I missed that, thanks for the clarification. The slowdown btw is in the Android system itself with adb reporting a VK_ERROR_DEVICE_LOST for the system services:
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