Lightdm doesn't show user desktop image when using custom image

I’ve run into a issue when using a custom desktop background image. When I boot up the login screen is blank. If I choose one of the system installed desktop images the same image shows on the login screen. After doing some searching I found most people saying it was just a matter of permissions to the image didn’t allow lightdm to open the image file to display it. I found that the default desktop images lived in /usr/share/desktop/. So I’ve tried creating a custom folder in that directory and it looks to have the same permisssions assigned as the cosmic, budgie, archlinux directories. but I still get a blank login screen. Here is an example of what the directories in /usr/share/backgrounds have assigned similar permissiosn to the files in each directory.

drwxr-xr-x - root 21 Nov 20:33  archlinux
drwxr-xr-x - root 26 Nov 16:01  budgie
drwxr-xr-x - root 21 Nov 20:33  cosmic
drwxr-xr-x - lightdm 23 Nov 11:58  custom

I’m not sure what I’m missing here. If I use any of the system installed images they are displayed on the login and budgie desktop. If I use a custom image that I place in /usr/share/backgrounds/custom or any of the other directories were other desktop images exist, it only appears on the desktop after logging in.

What am I missing here?