Hi big_smile,
Let's check to see if you have the option selected to blur the wallpaper, which is a feature designed to let app icons stand out. See step 4 in the following excerpt from a support article:
"Change the wallpaper
- 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."
Change the wallpaper on iPhone
Best regards.