Lofts between simple polylines create single unexplodable surfaces

I am trying to Boolean some simple lofted surfaces, but the lofted surfaces I create are problematic. I loft between two very simple polylines – for example, two house-shaped pentagons – but the loft created is for some reason a ‘single surface’ that cannot be exploded into 5 sides. When I try capping the lofted surface, it looks weirdly distorted. I believe this lofting problem is causing my Booleans to fail.

I have tried using every loft setting, but the result is always the same continuous single surface. Even lofting between two L shaped polylines creates a loft that ‘softens’ or sags in the middle! Why can’t it hold a strong edge?

Please see the images and the .3dm file attached.
Bad Lofting.3dm (113.8 KB)

It sounds like you have CreaseSplitting turned off.
Type CreaseSplitting and ckec the option. Then you’re get the joined surfaces you expect.

Thank you! Worked perfectly.

The mystery is how it was turned off, since my guess is you did not know the tool existed, and it is enabled by default…