CSS on Groups?

Lectora 11.1 - It seems we can't put css on a group of objects?

The option is there, but when clicking the Appearance lower-right icon to add a class, nothing happens. My questions:

1) Is this supposed to work?

2) If so, this may be a bug?

3) If groups can't use css, why is it available in the LEctora UI?

Thanks!