if parameters are not 0, null then limit will be PROFILES_PER_PAGE

if parameters are not 0, null then limit will be PROFILES_PER_PAGE

If you look at classes/User_group.php on line 412 in the current code, you can see that a call to $profile->getGroups() is made. This implies getGroups($offset=0, $limit=PROFILES_PER_PAGE) only giving a limited amount of groups.

This means only the first 20 groups in an ascending numerical order by locally stored User_group->id will be addressable with the bangtag syntax.

I solved this by making the getGroups() call to the same one made in Profile->isMember(), i.e. $profile->getGroups(0, null);