Wallpaper Bug

So I have this problem with the wallpaper that's included with the Niagara Launcher system. When I try to change the lock screen wallpaper only, it glitches and keeps the wallpaper the exact same. And the lock screen wallpaper is the same as the home screen wallpaper. I have a video for proof.

In the video, I tried to change my lock screen wallpaper only, but when I turned my phone off and back on again, the wallpaper stayed the same, and was the same as my home screen wallpaper. I was hoping this could get fixed, so I won't have to deal with this bug anymore. Thank you🙂‍↕️🫵