Problem Statement : MFA enabled user unable to login into Developer portal. We got fix as mentioned below
1. Log in to the admin console to your IDCS instance and go to Applications.
2. Select the application that controls your APIPCS instance.
3. Select the Web Tier Policy tab.
4. Scroll down to the Resources section, locate the /developers.* resource and select Edit from the hamburger menu next to it.
5. Change the Authentication Method value from public to oauth, and Save.
Now Developer Postal login will be controlled by IDCS. If that does not work immediately:
However, APICS instance does not have Web Tier Policy tab.