You still have "Legacy" mode on so in fact you are using surfaces and not seeing the building materials.
You can turn it off in Options menus > Project Preferences > Construction Elements...
It will be on by default for any file created in version 16 or before.
I need to type faster.
One of the forum moderators.
Versions 6.5 to 25
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Dell Precision 3510 - i7 6820HQ @ 2.70GHz, 16GB RAM, AMD FirePro W5130M, Windows 10