Inherited Security Groups

it is difficult to differ the set security group in child-entries, when it is not visible - or maybe not inherited?

example:
we have different security-groups for every team
every team has its folder
edit folder - set security group and activate "cascade security to children"

if i create a new sub-folder, there should be preselected the inherited security group but there is only <None> selected and "cascade security to children" activated

same if i create new entry in folder & subfolder .... security group is default <None>

How do I know now if it is inherited correctly - except testing with different users? Why it isn't pre-set in field?