Access Request Settings point to wrong site groups

Hi!

I'm having an issue with the Access Request Settings on a subsite, that was created by a previous colleague.  It it linked for some reason to the wrong set of Groups - so instead of being my site Owners, Members and Visitors, it is trying to pull the data from a different site.  

Has anyone had this problem before?  It's a pain because it means the only way to notify the Owners of the group is to enter their email - which is an issue as we have more than one Owner.