Are you asking about SSL or SSO? Or do you maybe have both? Is your SSL configured on the instances or offloaded by a load balancer? What is your SSO setup?
It was type error.. We have enabled SSO authentication.
Before upgrade do we need to do anything on SSO/
SSO should not be aware of or care about the database version used.
As you suggest, I recommend deregister and reregister with SSO of you cannot login properly after the upgrade as a first troubleshooting step.