Hi ,
- What type of lighting are you using for your scene/game? Static/Stationary/Movable?
- Is the light a Directional/Point/Spot light?
With mobile there are limitations when it comes to lighting. With static lighting you’ll need to make sure that you’ve built the scene to get the baked shadows working properly. This will not allow any shadow support for movable/skeletal meshes though.
If you’re using Stationary or Movable lighting this is only supported for a single Directional Light source and is not yet supported for point/spot lights.
Also, if you can, post a screen shot of what you’re seeing in the editor vs the device. This can also help. 
Thank you!
Tim