When changing the active layer to one that is currently invisible, its icon is not updated accordingly, i.e. to show that it is visible from now on.
I know, I know! Let me say that it is against my nature to change the active layer away from Layer0. I am just messing around with SketchUp Free to investigate its capabilities, which are great!
Unfortunately the feeling is as if I’m using an entirely different program, different from the desktop version, not so great