Thanks for this. It is interesting.
As you mentioned, Converting the Sandbox environment Portal to production is not possible. But the production environment should allow you to convert. The only other thing which I can think of is proper permissions. You must be assigned any of the roles for the environment.
- Global administrator
- System administrator
Can you confirm?
Hope it helps.
------------
If you like this post, give it a Thumbs up. Where it solved your request, Mark it as a Solution to enable other users to find it.