Blurred wallpaper lag on iPhone 13 Pro Max and iPhone 16 Pro Max

I've seen similar behavior on multiple devices — it's more of a system-level rendering delay than a true performance bug.

Here's what may be going on:

1. Wallpaper Blur Lag

When Face ID unlocks, iOS transitions the lock screen elements and applies the blur effect dynamically. On newer models, this should be smooth, but the blur layer can sometimes delay by a fraction of a second, especially if you're using a high-res image or a Live Photo as wallpaper. It seems more noticeable when there's contrast between the background and app icons.

2. Edited Wallpaper Reverting to Original on Unlock

This happens if the wallpaper was selected before you edited the photo in the Photos app. iOS may reference the original cached version. A workaround is:

◦ Re-save the edited version as a new photo

◦ Set the new version as your wallpaper from Settings > Wallpaper rather than directly from the Photos app

I have an iPhone 16 Pro Max on iOS 18.5 and was not able to duplicate your problem. I would try a Force Restart. Force restart iPhone - Apple Support

Try a restart.

Or turn off the blur and turn it back on.

I usually turn off the blurred home screen wallpaper.

Hard to say. The only way you can know anything like that is to have Apple look at the device and show them what you are experiencing. See this for making a Genius Bar appointment. Genius Bar Reservation and Apple Support Options - Apple

If you edit a photo it does not update the wallpaper that may contain it. You would need to delete the wallpaper and recreate it, not that it would fix your problem.