Unchecking of the category for an asset does not work

We have a category defined for an asset in the following way :
                   Lifecyle Actions
                                    (checkbox) Image
                                                           (checkbox)Provision
                                                                               (radio button) enabled
                                                                               (radio button) disabled
                                                            (checkbox)Clone
                                                                               (radio button) enabled
                                                                               (radio button) disabled      
Once a category is applied to an asset ,we are not able to uncheck it and completely remove it.
It just says that a child item has been selected.

Is the configuration wrong?

we are uisng RAM 7.2.