SCIM 2.0 Provisioning - An error occurred while pushing a profile update to this app

Hi Team,
We have our SSO App published in OIN. Now we are enabling Provisioning option in the same App. While trying to test our API Server implementation by Runscope, The users are created in SCIM App. But the update is not working. The update request is not sent from Okta to our App.

We are facing the same issue while trying the profile update through Okta UI. The Provisioning settings and External Id are fine. The Message we get is “An error occurred while pushing a profile update to this app. Automatic profile push of user to app failed.”.

Could you please let us know the way to make the profile update work. Do we miss anything?
Thanks in advance.