Display Mesh in Power InRoads

I'm reviewing a DTM from another firm and as part of that check, I'm doing some AutoTurn Pro analysis.

I'm attempting to load the DTM as Triangles. In my past experience, I do that by setting the DTM as active, going to Surface --> View Surface --> Triangles. After that, a window pops up that typically let's me select "Mesh" and change the color of the triangles if I want to. Now, after selecting Triangles, the triangles just show up in my model space, but not as a mesh, as separate triangles which I can not use with AutoTurn Pro (that needs a mesh surface). Does anyone have any ideas?