How do I remove a group from the Repositories folder permissions?

I have a group that has been added on the main "Repositories" folder:

I am trying to remove this group from this list, but when I click the "Remove" button, it converts to

and does not remove it from the list. I can then manually remove permissions and set it to "No Access."

The group is not on the Data Services Application for permissions, either.

I am not sure how to remove this group from this list completely, I have thought that perhaps the "Reset Security Settings" button will do this, but because it also seems possible this will reset all security settings I am scared to click it...