Fills display funny in section

[Steve Jepson]

This is interesting. Make a section parallel with/in a composite wall and see the fill.

[Barry Kelly]

I'm guessing you have insulation in your wall.

I bet your insulation fill is set to "fit to skin" in the building material.
Normally in a perpendicular section this would be fine.
But because your section is parallel then it is now "fitting" to your wall perimeter here as well.

It happens in other versions as well as 17.

Barry.