OHIF sends an options requests for each get request after including Authorization Headers

I’m using the newest release 3.7 of OHIF.

I have OHIF connected to Orthanc running on a windows VM and using IIS in front of it. I use HTTP Basic Auth attached to the headers of every request sending from OHIF to ORTHANC.

However, when I setup these headers, OHIF or the browser sends an options requests before every single request, basically doubling the amount of requests I make to my VM running orthanc.

Is there a way to stop this or improve its performance? I set the Access-Control-Max-Age in IIS but it doesn’t seem to be working because the options requests are still being sent.