Users report that after updating to iOS 27, external video playback via HDMI stops when the iPhone screen is locked. Previously, video output continued even when the device was locked.
Testing confirms that apps like YouTube and Netflix are affected by this issue. In contrast, the VLC player continues to output video to external displays normally after the screen is locked.
The issue may stem from changes to system permission mechanisms. iOS 27 now requires applications to explicitly register external display video sessions, whereas these permissions were handled automatically before.
As a temporary workaround, users are keeping their iPhones unlocked with low screen brightness to save power. However, this approach carries the risk of accidental touches, particularly when using AR glasses.
The problem was first reported in September alongside the release of iOS 27. As of the latest report, the issue persists in iOS 27.2, and there is no official timeline for a fix.
