User level: Level 1 (13 points)When playing 4K videos shot on the iPhone 18 Pro, grid lines appear. (Including when 4K videos captured on my iPhone 14 Pro and Oppo phone are transferred to the iPhone 18 Pro for playback, grid lines also appear.)This issue (grid lines) does not occur when taking photos.
The issue was resolved after restarting the phone, and the grid lines disappeared. However, some users report that the problem (grid lines) reappears several days after restarting.
Posted on Sep 26, 2026 10:36 PM
User level: Level 10 (454,138 points)Sep 26, 2026 10:53 PM in response to Brandon-CN
Send the original video to another device — your Mac, Windoes PC, another iPhone, or upload it to WhatsApp/Instagram/Telegram without editing it.
If the grid disappears there, the grid is not in the video file. It is being generated during playback/rendering on the iPhone.
If the problem is occurring in the scaling/rendering stage, changing the zoom changes the way the underlying rendering tiles are mapped onto the display.
That explains the behaviour reported by several iPhone 17/18 Pro users:
User level: Level 1 (13 points)Sep 26, 2026 11:15 PM in response to SravanKrA
Thank you. I transferred the 4K video shot on the iPhone 18 Pro to my iPhone 14 Pro and OPPO phone, and no grid lines appear on either device.
When the grid shows up on my iPhone 18 Pro, pinching to zoom in on the video makes the grid disappear.
Originally posted at discussions.apple.com/thread/256365775