1. iOS 16 Bug
Many users noticed wallpaper disappearing or going black after updating to iOS 16.1. Apple patched most of these issues in later updates (so updating iOS helps).
2. Low Power Mode
If Low Power Mode is turned on, sometimes dynamic wallpapers or effects don’t display correctly. Fix: Go to Settings > Battery > Low Power Mode → Turn it off.
3. Live / Dynamic Wallpaper Glitch
Live Photos and dynamic wallpapers (like earth, weather, astronomy) sometimes go black if the phone runs low on memory or after a restart. Fix: Switch to a static wallpaper (Settings > Wallpaper > Choose New Wallpaper).
4. Focus Mode / Lock Screen Link
In iOS 16, wallpapers can be linked to Focus Modes. If a Focus is triggered, your wallpaper may change—or turn black if something went wrong. Fix: Go to Settings > Focus, check each Focus, and unlink wallpapers.
5. Corrupt Wallpaper Image
If you’re using a custom photo that’s damaged or not fully downloaded from iCloud, it might appear black. Fix: Re-download the photo from iCloud or choose a different one.
6. System Cache / Temporary Bug
Sometimes iOS simply glitches. Fix: Restart your iPhone → Settings > General > Shut Down.
How to Fix It Quickly
Update to the latest iOS (go to Settings > General > Software Update). Turn off Low Power Mode. Re-apply your wallpaper from Settings > Wallpaper. Test with a different wallpaper (photo vs. live vs. dynamic). Restart or force restart your iPhone.
If the wallpaper still goes black even on the latest iOS, it might be a deeper system issue → consider Reset All Settings (Settings > General > Transfer or Reset iPhone > Reset > Reset All Settings).