I already reported this on github - this is just for the information of other users:
There seems to be a bug in saving group information. I noticed it, when trying to display some badges for certain groups. I faced the situation on
Steps to reproduce are:- Admin->Manage->Groups ->click'Show Badge' - Saving information 'Success Changes saved!' is displayed - Leave Page ->'You have unsaved changes. Are you sure you wish to navigate away?' is displayed - Re-check resent changes: Changes not saved for checkboxes: 'Show Badge', 'Private', 'Disable join requests', 'Disallow users from leaving the group', 'Hidden'