I have an AD group "superusers" which has direct access to some list items in a list. Using Check Permissions show that even though the AD group is listed with access to the list item, it does not have access. User in AD group can confirm this. See this screen shot of the issue:
Can anyone explain this behavior and possible fix?
I have seen various people having an issue where users recently added to an AD group do not get access due to SharePoint caching of security token, however, this is not the issue here.