Getting 500 error while calling graph client's create_group function

Objective: I want to add a MS Entra group to a ADO Group. I can successfully do it using the API POST https://vssps.dev.azure.com/<>/_apis/graph/groups?groupDescriptors=vssgp.Uy0....&api-version=6.0-preview.1

but whenever I am trying to use the following code I am getting a 500 error:

class GraphGroupOriginIdCreationContext(GraphGroupCreationContext):
_attribute_map = {
'origin_id': {'key': 'originId', 'type': 'str'}
}
graph_client = connection.clients_v6_0.get_graph_client()
def init(self, origin_id=None):
super(GraphGroupOriginIdCreationContext, self).init()
self.origin_id = origin_id

new_group = GraphGroupOriginIdCreationContext(origin_id="<>")

graph_client.create_group(new_group, group_descriptors="vssgp.Uy0....")

Can anyone tell me where I am getting it wrong or is this a bug?

Start at the graph_client.create_group call and compare its arguments with the working Azure DevOps POST endpoint shown in the issue. Inspect how GraphGroupOriginIdCreationContext is passed to the client and determine whether the 500 error comes from client usage or the library; done means documenting the cause and confirming the appropriate correction.