@RRompich - honestly, I don’t think you are making the API call you think you are here. Its a bit obscured by the hubspot client code library conventions.
Although the original thread suggested a v3 objects API, I would be very tempted to directly use the most current v4 API code for this:
GET/crm/v4/objects/{objectType}/{objectId}/associations/{toObjectType}
Which will list all types of associations - HubSpot and user defined - although that may not be as useful here as it is in other places.
I tested this out and it seems to provide full information required.
Hope this works for you!
Steve
``