@Chinmay Sonawane Thanks for reaching out. It appears that the issue you are experiencing is due to the fact that both portals are using the same content, which is stored in the same APIM service. This is expected behavior, as all portals in the same API Management service share the same content.
To differentiate the appearance and functionality of each portal, you can self-host them with your own custom widgets that dynamically customize pages at runtime. This can be done by creating custom JavaScript code that runs on the portal pages and modifies the appearance and behavior of the page based on the URL or other criteria.
For example, you could create a custom widget that changes the font color or adds new text based on the URL of the portal. This would allow you to differentiate the appearance of each portal while still using the same content.
do let me know incase of further queries, I would be happy to assist you.