For detailed info regarding the RFE please check this issue already reported at ArgoCD and they are targeting to fix in 2.1 release:  https://github.com/argoproj/argo-cd/issues/6857

1. SSO issue with existing OIDC Provider | Argo logs and argocd.token cookie token don't have requested scopes.

2. In order to use GitOps/Argo OIDC | SSO Integration is failing due to not having requested scopes.
Configure Argo CD to use an existing OIDC provider as per the documentation and notice /authorize call made to the OIDC provider when requesting configured scopes. The call is sending plus signs instead of encoding space characters as %20. This is causing an issue on the provider end and not returning the requested scopes.

3. Customer’s Environment required Argo CD working with OIDC provider integration.

4. List of affected packages or components.

• ArgoCD
• GitOps Operator
• OIDC, SSO