Character's shadow showing on mobile preview, but not iPad

I’m using stock UE 4.6.1. In my scene, I’ve one single directional light which is set to movable. It also has all the cast shadows flags set. In the mobile preview, character shadows are showing. However, when I package and run it on the iPad 4 (iOS 6.1), the shadows aren’t visible. Is there perhaps any settings that isn’t correct? I’m using a project setting of mobile/scalable, and tried both enabling and disabling mobile HDR. Or perhaps, does the receiving surface/material (static mesh) need any particular setting?