In CAF, for each service, you may provide the “authentication info”, which imho it’s not recomended when you deal with multiple environments. Instead, pass the user id as a parameter to the service.
Trying setting your Web Service Connector’s authentication info to use “hybrid” (type 3) authenitication. This will use SAML for web service Single Sign On.
You’ll need to make sure that IS properly configured for SAML. There is an older Tech Note link below that is a bit dated, but covers the subject pretty well. One major difference is that the SAML Revoler URL is now in the Resources category of the IS admin pages.