setupGroupSelect needs reload


In our app we need the possibility to select groups. We used a text field, but it will be easier if one can select the group from a list. I wanted to do this with OC.Settings.setupGroupSelect().
Our configuration is in the admin navigation under additional. If I click on additional, this field is empty. I have to reload the page. When I use exactly the same code with a text field instead, it's working without the reload.

Are there any idea?

Thanks and regards