I think I've bumped into a bug in 2.3RC3. Can someone please confirm this behaviour before I open a new ticket ?
If I try to set a a View Group in the Access Tab (Who can view this page --> only these people) and press "save and publish" , Silverstripe does not store my selection. If I press save (to draft) and immediately (without leaving the page first) press "save an publish" it works properly.