Underground belt autoplace

[Commandervander]

I placed a blueprint for a furnace array that involved underground belts going under power poles (this is before robots). To construct the array, I began by placing power poles, then clicking and dragging a belt so that underground belts would (in theory) auto place. Instead, the first underground belt, before the obstacle, places correctly, but the output underground belt remains a ghost.

This could be intended behavior, but it doesn't seem like it