Treeview DateTime render error

I've configured the Treeview widget with 4 entities, the context object and 3 nested ones. So I've configured 3 relations, for each of the 3 child objects. In rendering, I've configured 6 objects. For nested entity level 1, I've only configured a name. For level 2, I've configured a name and a date. For level 3, I've configured a name, date and a numeric score attribute. For the date/time attributes, I've set the custom format to dd-MM-yyyy. However in the application, the Treeview renders the date attributes incorrectly: NaN-NaN-NaN. I know for sure that the date attributes are filled. Am I doing something wrong or is this a bug?
1 answers

This seems to be not a known issue. I suggest filing a support ticket.