Web service user unable to log in to exposed web service

Hello everyone, I have created an exposed web-service, with authentication, and I tried to use login details of a web-service user account to access the endpoint, I set up the roles allowed  to access the resource as followes  but every time I send a request i receive with a web-service user I receive the following message: Outgoing REST response: HTTP/1.1 401 Cache-Control: no-store Date: Wed, 22 Aug 2018 16:02:37 GMT Content-Type: application/json;charset=utf-8 WWW-Authenticate: Basic {"error":{"code":401,"message":"Provided username-password combination is invalid."}} If I use a normal user with the DynamicsUser role the microflow behind the resource triggers and everything works perfectly. My question is how come I get an authentication error when I use the web-service user? I was expecting that exposing a REST service will work exactly like exposing a SOAP service,   I ask this because I have the same exact microflow exposed as well as a SOAP service, and it works perfectly when I access it as a web service user.
1 answers

Because it is not supported. But I agree it is strange.

Note that web service users cannot access REST services.