Wallpaper keeps disappearing on lock screen after latest update

Hello adang-1988,

With iOS 16 it is possible for wallpapers to be linked to different Focus modes on your device.

From what you've described, you may be experiencing a change in wallpaper when a Focus changes on your device until you restart it.

Check out the following article: Use Focus on your iPhone or iPad - Apple Support

Specifically "Connect Home Screen pages to Focus,

1. Go to Settings > Focus.
2. Select the Focus that you want to customize, then choose the Home Screen.
3. Create a new Home Screen page, select an existing Home Screen page, or select multiple pages that you want to connect to this Focus.
4. Tap Done."

Let us know if this helps.

Cheers!