How to move the site to a different URL keeping the theme registration

Hi,

we have been developing a new version of a website for a while.
The old one is here:
https://www.pastoraldelsord.org
the new one, using the Newspaper theme, is here:
https://v2020.pastoraldelsord.org

During development, the theme was registered ok using the temporary URL.
Now that we want to move it to the real production URL your theme seems to deactivate itself with no possibility to activate again.
We have restored the changes and went back to the development URL, then we could Reset the registration key.
Then we tried moving to the new url and do the proper activation. We enter the envato purchase code and it simply doesn’t work. Even worst, back to the development url the activation won’t work anymore. It accepts the purchase code and presents the forum registration form, but after reloading it is still unactivated.

Can you help us?

Have you even read my message? I know how to activate the theme, I did it in the development version the first time. Now I cannot activate it anymore.
I’m attaching some captures to see what happens:

https://imgur.com/a/Xlg4zDb

1) Install required plugins (they were already installed, but got deactivated by your theme when changing the site url)
2) The theme appears installed, only missing activation
3) When accessing the activation page

If I go back to administration, I just get the first screen.

I can give you access to the site administration if you need to check the problem.