This is happening due to how the staging environment works essentially.
Usually, if it was not a staging copy, the solution with:
Would be applicable. But in this case, it is not (as it gets the whole site in a redirect loop).
What I can suggest is to clone the application separately onto a different subdomain (for instance) - without using the staging tool for you. Then you can make the necessary changes via the X PRO builder. Or my other suggestion would be to try and use a different builder for the staging copy, which would not have the same issue.
So I guess nothing can be done if you have your domain with siteground can it?