Hi Andy,
Did not fully understood your first question. If it works via application (SP initiated login, it should also work fine for IdP initiated login. However in an IdP initiated login IdP may not know to where redirect the browser. Kindly check the help message near the checkbox for that configuration: "When activated will allow IdP Server Initiated login, ie, without the need of previouly this connector sends an Authn SAML message. When activated most probably you also want to configure a "Login Default URL""
Meaning that without a "Login Default URL" configured (on the same third tab) the browser most probably will be redirected for "/" URL, which in your installation must being redirected for the service center.
Regarding the second question, the Single IdP should be enough for all your applications (including multi tenant scenarios).
The use case that in fact it's not supported to use the same IdP application, is when your applications have different UserProviders (the UserProvider of IdP connector must be the same of the applications that rely on it).
Regards
Thank you very much for the tip. Now, both the clicking Okta app icon and typing app URL work fine.
You are right. It is the Login URL in the 3rd panel. I need to populate it with the app URL.
In terms of the unclear part of my previous question, please allow me to clarify it more with example:
Let's say I have two apps in Outsystems - app A and app B.
Correspondingly, I will have two apps created in Okta to talk to app A and B (hopefully I'm correct at this stage..).
Now my confusion is - in the IdP component configuration, the 1st tab can only take metadata file from one Okta app. And in the 3rd tab, if I have populated the login URL with the specific app URL, how can I make the IdP work for both or more applications?