API request returns string instead of object

Hey guys,
I have a little problem: For some reason the following request returns a string as a response and not an object. All other requests in advance (which fill regEntry) work perfectly. The association is generated correctly. However, the answer is of the wrong data type.
I know I could work with JSON.parse (), but the API documentation clearly says that an object will be returned and that I should be able to rely on.

Any ideas?
I tried the following header

headers: { accept: 'application/json', 'content-type': 'application/json' }

headers: { accept: 'application/json' }
var requestAssocDealToContact = {
 method: 'PUT',
 url: 'https://api.hubapi.com/crm/v3/objects/deals/' + regEntry.deal.id + '/associations/contact/' + regEntry.contact.id + '/deal_to_contact',
 qs: { hapikey: apiKey },
 headers: { accept: 'application/json', 'content-type': 'application/json' }
 };

 request(requestAssocDealToContact, function (errorAssocDealToContact, responseAssocDealToContact, dataAssocDealToContact) {
 if (errorAssocDealToContact) 
 throw new Error(errorAssocDealToContact);

 regEntry.assocs.contactToDeal = dataAssocDealToContact.id;

 responseJson.botMessage = typeof dataAssocDealToContact;
 responseJson.customState = regEntry;

 callback(responseJson);
 });

Nevermind :slightly_smiling_face:
Accidentally deleted

json: true

inside the request object.
Thank y’all!