Hi everyone,
I'm using an iPhone 13 running the iOS 27 Public Beta, and overall the experience has been excellent. Battery life is better than I expected, and the system feels very smooth during everyday use.
However, I'm experiencing one persistent issue while playing Call of Duty: Mobile (CODM).
Whenever an iOS system UI appears, the game briefly stutters or drops frames. This happens with:
Pulling down the Notification Center The volume indicator (Volume HUD) Other iOS overlays or system UI animations
The stutter only lasts for a moment while the UI is displayed, and gameplay immediately returns to normal if I open the full control center (swiping down). The frame drops will be also gone when I change the frame rate from MAX to Low then Low to MAX frame rate.
Things I've already tried:
Restarting the device -Enabling Shader Preload in CODM -Closing background apps
-Testing different graphics and frame rate settings (which is a temporary solution)
-Updating to the latest iOS 27 Public Beta
The issue was also present on my previous iOS version, so it doesn't appear to be new to this beta.
During normal gameplay, the game runs smoothly. The frame drops only occur when iOS overlays are rendered.
Has anyone else experienced this on iPhone, particularly on iPhone 13 or other models? I'm also curious whether this is an iOS compositor issue, a CODM optimization issue, or simply expected behavior when system UI interrupts a game.
Any feedback or suggestions would be greatly appreciated. Thank you!