OAM 11.1.2.1.4, SSO in multiple domains

In our environment, we use OAM 11.1.2.1.4 as SSO solution.

We have 2 domains that hosts 2 different applications:

domain_1 -> hosts app_1, also used for our custom login page and oam (so requests to /oam/* is using domain_1)

domain_2 -> hosts app_2

We've configured the resources and policies as follows:

1- Some resources are protected and requires authentication

2- Some resources are protected, but doesn't require authentication "using public resource policy"

3- Some resources are excluded

- For both 1 & 2, we've set responses in the authorization policy, to return some user attributes, like user_id for example

We've used the above configuration and it was working fine while we were using IPs. Now when we tried testing using domain names mentioned above, we noticed the following behavior: