Your issue is more than likely that you included the Unity skybox when you uploaded your scene.
Fortunately this is an easy fix, in unity navigate to Window/rendering/lighting/settings/environment and set the skybox to 'none'. Reupload and your scene should work.
This skybox issue is also mentioned in the STYLY manual for AR.
I've uploaded an animated scene from Unity to STYLY AR. The scene looks good in a browser but for some reason the Scene wont display properly when i test it on a mobile device. I'll get flashes of my model and occasionally it looks like the default Unity fskybox will occasionally block out my whole screen. What have i done wrong?