I've been using Fences 2 for several years and have had no real problems with it. I just upgraded to Fences 3 and now the transparency is not working properly.
I'm running Windows 10 with two screens, and I have different wallpaper on each screen. I have all my Fences on Display 1, but the transparency image that Fences displays is from Display 2, example:

Please let me know if you need any more information.