Unable to edit the value "non worker type"

Content

Hello,

what i noticed is that the non worker for who we were able to associate the payelemet have the "non worker type" setted on "nonworker paid". All the non worker for who we were not able to associated the pay element have this value setted on "nonworker unpaid".

Now what i made it was to search these non worker and click on edit in the manage employment page but it is not possible chanege this value. The filed is editable but i can't select the value Nonworker paid because the value there is not.
How can i change thi value?