No permissions after adding a folder to warp/databox

[shouben]

setting up acl is not deterministic
We can sometimes succesfully give access to folders and files.
In other occasions (following the same procedure) this is not possible.

Created a folder nee and folder nee2
Changed the permisions:
https://z-koo.com/people/houbens.at.gmail.com/card#me
https://z-koo.com/people/clerris.at.gmail.com/card#me

Han/Sonja both have access to: http://linkeddata.github.io/warp/#/list/https/databox.me/nee/
Han/Sonja have NO access to: http://linkeddata.github.io/warp/#/list/https/databox.me/nee2/

This is tested by 2 persons in chrome browser on laptop (windows 7 and macbook)

could you explain what we are doing wrong or what the issue is?