Impossible to define group properties in group of groups
When having a conflict of groups properties (ie: 2 groups without common parents that define the same keys, and are applied to a common node)
a good solution is to define a group of group to resolve this conflict for this specific case.
It works well, but then, this new group can not define nor retrieve its own properties. I always end up with an error message when visiting its page in the UI.
Also, I can not see nor define new properties for this group.