Skeletal meshes are not simulating physics

Skeletal meshes do not simulate physics when playing in viewport. They are not affected by gravity, nor do they ragdoll.

This doesn't occur in UE4/Main. This occurs with Immediate Mode Physics off and on.

1. Open QAGame in editor.
2. Drag a skeletal mesh into the level.
3. In the Details panel, enable Simulate Physics.
4. Simulate in viewport.

RESULT

Skeletal mesh doesn't simulate physics