Angular on IIS - How?

Hello All,

I am new to Okta.

I have successfully used the SDK to create test apps (Angular 13/14) in local dev environment.

The Okta App is configured as SPA, PKCE, OIDC,

The attempts to the publish test apps to Staging and Production IIS servers (2016 and 2012r2) have not been successful.

Confirmed:
No angular route hash ( # fragments not allowed in OIDC auth)
The Sign-in redirect URI is confirmed and all lower case (each environment dev, staging, production)
IIS has URL Rewrite rules are in place. Also tested without them. Same results

Issue presents as:
403 - Forbidden: Access is denied

Question:
What is different in the default IIS “Static App” index.html default document application setup than testing the same app in Angular development environment.

In other words - I assume many people have successfully deployment Okta protected Angular apps to IIS. I have reviewed dozens of posts and almost all point to one or more of the three items that I have listed. What should I check? Can anyone point me to the documentation that I may have missed. Thank you in advance.