Adobe SSO and Workday Integration

Hello, we have been setup with Adobe Sign and Workday (using integration key) for quite some time. About a year ago, we switched to Enterprise/Federated/SSO and ever since my HR users and those, who need to sign in certain letters in Workday are unable to do so with their Federated Adobe accounts. Only if I override the setup and create a business, password protected account (with identical name of course), does Workday work. Adobe Enterprise support points to Workday as the owners of the integration. There's no documentation availabe on how the users themselves need to be setup (Federated vs Business). The integration account itself does not have SSO and is otherwise working perfectly fine. Does anyone else have the same problem? Our organization can't be the only one. Thank you.