Hi there,
After long hour checking, we found out that 31 registered user is in pending state(state='4') as shown below.
SELECT count(*) FROM `iph86_social_clusters_nodes` where `state`=4 and `cluster_id`=9; (user under pending mode) 31
SELECT count(*) FROM `iph86_social_clusters_nodes` where `state`=1 and `cluster_id`=9; (user already joined)846
SELECT count(*) FROM `iph86_social_users`; (total of the site member) 884
846 + 31 = 877
884 - 877 = 7 (the rest of the user is under `Dealer / Business Account` profile type which do not have auto join group feature)
if you want to enable all you can just run this query below.
UPDATE `iph86_social_clusters_nodes` SET `state` = 1 where `state`=4 and `cluster_id`=9;
p/s: You can contact your database service provider for further check on this issues.