Microstation Terrain to ORD Terrain

How can a Microstation Terrain be given civil rules i.e. turned into a ORD Terrain?  For context the Terrain has come from a STM.

I've tried to follow the official documentation i.e. Set Feature Definition, select Terrain category: https://communities.bentley.com/products/road___site_design/w/road_and_site_design__wiki/21738/use-scalable-terrain-models-in-openroads

But nothing happens, no errors etc., just says as a Terrain. Tried changing the Terrain resolution and extents but no difference. Also tried leaving it as no feature definition.

Any ideas?