iPhone owners report that video playing on a TV, monitor or display glasses over USB-C to HDMI stops as soon as they lock the phone. GSMArena reproduced the problem in YouTube and Netflix, and iOS 27.2 hasn’t changed it. For now, the only workaround is to keep your iPhone unlocked.
What changed in iOS 27 for HDMI video
The habit used to be simple. You plugged in an adapter, started a video, locked the phone and kept watching on the big screen. According to GSMArena, the problem was first reported in September alongside the iOS 27 release.
That habit no longer works in YouTube or Netflix, based on GSMArena’s tests. VLC kept playing normally in the same office tests.
GSMArena traced the problem to a change in how apps get access to an external display. Apple’s developer documentation says that from iOS 27, an app gets a dedicated external-display scene only after registering for one. In earlier versions, iOS connected that scene automatically. The documentation doesn’t mention locking, so the link to playback stopping on lock is GSMArena’s reading.
Why this lands on users, not just developers
Apple changed the rules for app makers, but the result for viewers is a feature that stopped working. A fix now depends on each app being updated for the new requirement. Which apps beyond those tested are affected is unknown, and so is the timing of any YouTube or Netflix update.
As of November 7, we found no Apple statement on the lock-screen behavior. Apple’s developer page explains the change to developers, but we found no user-facing note telling iPhone owners about it.
Display glasses owners have it worst. Glasses like the XREAL Air 2, which GSMArena names as an example, are built around video output with the phone tucked away. Keeping the iPhone awake makes that setup awkward for anyone using glasses such as the XREAL 1 Pro+ on a train or plane.
Infuse users report a related iOS 27 problem
A separate symptom shows up on the forum for Infuse, a popular video player. Users say that since iOS and iPadOS 27, Infuse falls back to plain screen mirroring on an external display instead of a dedicated video output. That is a different issue from playback stopping on lock. Firecore staff member James replied to those reports on September 22:
This seems to be a new behavior with iOS 27 and we’re looking into this.
The thread is still marked in progress. The latest user posts, from October 23, report no fix. It’s not the only external-display change of this cycle either: an iPadOS 27 AirPlay change can put private presenter notes on the projector.
Workaround until apps are updated
- Keep the phone unlocked: leave the iPhone awake while the video plays, and avoid touching the screen.
- Lower the brightness: turn the phone’s screen down to cut glare and save some battery.
- Try another app: VLC kept working in GSMArena’s tests, so it’s an option for local video files.
If you rely on an HDMI adapter or display glasses, retest your video apps after each app update and each iOS point release. The iOS 27.2 update wasn’t the fix, so app updates are the more likely route.
Source: GSMArena, Apple Developer, Firecore community forum
