When I disabe DS the desktop still appears with a frozen image of the Dream I was running,
I'm seeing this on Beta 2 as well (Win10 ver 1809 build 17763.379). Wasn't seeing it on the 1st Beta, at least on my non-admin Standard user which I typically use. Also, after disabling Deskscapes, changing the wallpaper via Explorer right-click or Personalize doesn't change the wallpaper until after logoff/login.
Admin user goes to a blank black screen similar to what was described in Reply 95, only black. Don't really know if that was happening on Beta1. Logging into Admin without Deskscapes enabled initially shows the wallpaper, but then after the first screen refresh, either automatic or manual, it switches to black. Applying a wallpaper within deskscapes works, but then disabling deskscapes throws it back to black.
I'm not running any additional wallpaper managers at all, and a single monitor.