To reproduce the issue follow the steps:
1. Open project user has attached
2. Open "Dx11GeomertyShaderBug" scene
3. Observe wireframe shader cube in the scene
4. Play the scene in DX11 (NVIDIA GeForce GTX 970/980)
5. In play mode cube appears to be solid instead of wireframe

Result: Solid cube is being rendered

Expected Behaviour: Wireframe cube is rendered

Everything is fine on GLCore

Reproduced in 5.4.0b12, 5.4.0b16, 5.3.4p1, 5.3.4p1