After installing the latest version, the wallpaper now doesn't change. I have it set up to select a different wallpaper from a selected folder. However, the wallpaper doesn't change. I tried doing manually and on the setup screen it shows the new wallpaper but it doesn't apply it to the desktop.

No it doesn't. I also had to apply Admin rights on the app as it would continue to request administrative rights but it wouldn't load. So there seems to be an issue with window's security. Not sure if maybe the latest window's update could be causing any issues? I have the Window's Pro Insider preview.