vRO 6 - AD Plugin - get AD Users' group membership

I want to get the AD Users group membership using the plugin.

There are two methods I have tried and both fail:

1.

ADUser.getAttribute("memberOf");

- this returns only the first group the AD user is the member of; In the AD the groups (group DNs) are separated by semicolons - why is only the first value returned?

2.

var ADGroups = new Array();
ADGroups = ADUser.memberOf;

- this should return an array of AD:UserGroups, the number of returned groups is correct (checked with .length), but each value is null:

for each (ADGroup in ADGroups){    System.log(ADGroup.getAttribute("distinguishedName"));
}

output: TypeError: Cannot call method "getAttribute" of null

What would be the correct way to return an array of groups the Ad user is a member of?

Edit:

I've tried to use the newest 3.0.0 plugin from here too: Technical preview version of VMware vCenter Orchestrator Plug-In for Microsoft Active Directory