Access permissions not unchecking

I am having an issue when editing a document, I can’t uncheck any of the Access permissions. Let me re-phrase that: I can uncheck them, and save the document, but when I edit the document again, the permissions are checked again. I am the administrator role.

I am new to modx (I’m taking over a website built with it), and am confused by this behavior. Any ideas what is wrong? (I’m using version 0.9.6.3