Moodle 2.3.2+ (Build: 20121018), Certificate version 2012092101.
I have a certificate in a course setup with groups for each school. Currently over 1500 users have received a certificate.
For 'all participants' I can click on 'view xxxx issued certificates' and receive the listing, download excel, etc.
When I select any group, I will see for example 'view 15 issued certificates' but when I click the link I get 'there are no certificates that have been issued'.
I can find the 15 users in the full list so I know they have certificates in the system.