Change Lock Screen without changing Home Screen

Hi JustLookingForHelp12,

What you're currently seeing is expected behavior. You will need to manually change the Home Screen now. Check this out: Change the wallpaper on iPhone

Change the wallpaper

1. Go to Settings  > Wallpaper, then tap Add New Wallpaper.

The wallpaper gallery appears.

2. Do one of the following: 

Tap a button at the top of the wallpaper gallery—for example, Photos, People, Photo Shuffle, Emoji, or Weather—to design your wallpaper with a photo, an emoji pattern, a picture of your local weather, and more.

Tap a wallpaper option in one of the categories—for example, Featured, Suggested Photos, or Photo Shuffle.

3. To customize a photo on your wallpaper, see Customize your Lock Screen photo.

4. Tap Add, then do one of the following:

Choose whether to use the wallpaper on both the Lock Screen and Home Screen: Tap Set as Wallpaper Pair.

Make further changes to the Home Screen: Tap Customize Home Screen. Tap a color to change the wallpaper color, tap  to use a custom photo, or select Blur to blur the wallpaper so the apps stand out.

Have a nice day.

Hey JustLookingForHelp12,

It looks like you checked out the article about changing your iPhone wallpaper. We'd like to also share this user guide that goes over the steps you can take to personalize your iPhone Lock Screen: Personalize your iPhone Lock Screen

We hope this helps!

Best regards.