data API for agent contact returns 404

We have a ticket page plugin that uses the contact/data-API function, to determine whether the current ticket's contact an agent or a customer.

https://developers.freshdesk.com/v2/docs/data-api/#contactAPI

Since last week (~2019-02-06) this method call returns a 404 instead of a contact object.

Previously we used the result to get the flag result.contact.is_agent

Was this changed, or is there an alternative? I didn't find any documentation about possible error codes.

c.data.get("contact").then(r => console.log("Is agent? ->", r.contact.is_agent))   

c.data.get("contact")
     .then(
          r => console.log("Is agent? ->", r.contact.is_agent), 
          e => console.log(e));
    

Here an example of the error logs in the console in case the requester was an agent. 

c.data.get("contact").then(r => console.log("Is agent? ->", r.contact.is_agent), e => console.log(e));
Promise {<pending>}
new-relic-10cd82f5c7…86e1796fcf7927.js:1 GET https://potix.freshdesk.com/api/_/contacts/5000493461?include=company 404
vendor-10cd82f5c7e2e…6e1796fcf7927.js:77 
i {isAdapterError: true, description: undefined, fileName: undefined, lineNumber: undefined, message: "Ember Data Request GET /api/_/contacts/5000493461 returned a 404↵Payload (Empty Content-Type)↵ ", …}
vendor-10cd82f5c7e2e…6e1796fcf7927.js:77 
i {isAdapterError: true, description: undefined, fileName: undefined, lineNumber: undefined, message: "Ember Data Request GET /api/_/contacts/5000493461 returned a 404↵Payload (Empty Content-Type)↵ ", …}
VM1004:1 
{message: "Request timed out!"}

In the end the error message simply says "... Timed out!" ... which looks like a bug to me. As mentioned above this used to work before the update last week.