invalid_argument msg

I have an existing application that works using Zitadel as the IdP. I am integrating a third party using their Okta and generic OIDC for authentication.

Once enabled I have the sign in button using Okta as IDP and that flow takes the client to their Okta page. They are able to provide login get to the callback of my Zitadel instance but get the attached error message.

We have tried changing settings on both side but as a managed client I have no idea what is wrong or even how to debug this issue.

Any ideas or help on how I can trouble shoot would be most appreciated.

Thank you