Hi @nish.joseph and welcome to the Mautic Community Forums! Thanks for bringing the conversation over here from Slack 
From what I can see you have two issues here:
- SSO failing to authenticate on submit
- Unable to update the SSO settings
Regarding #2, I found this github thread: https://github.com/mautic/mautic/issues/7294 which suggests this Pull Request might fix the problem: https://github.com/mautic/mautic/pull/7305.
Maybe if you can try to apply this PR, and see if it fixes the problem? If so, please report it as a successful test by going to the PR, clicking on ‘files changed’, click ‘review changes’, add a comment and select approve changes.
If you need help applying the PR let me know 