Moving from Postman to Yaak, mtls cert inconsistency

I can make, what i believe to be, the same request using the same pfx certificate to the same endpoint and get 2 different results.

In postman i get a 200 and expected response, in Yaak i get a Error 403 - Forbidden: Client Certificate Required

not really sure what the difference is.

Also I’m not really allowed to provide certs for debugging though but if required i could perhaps provide requests and partial urls to aid in this.