Yes, sorry, with your setup you’ll either need two licenses or juggle the activation of the license between the sites. Generally, I advise leaving the activation on the live site. Now, if your sandbox is actually a staging site, meaning all updates and changes occur there then are pushed to the live site after testing, then, leave the activation on the sandbox site and not worry about the live site. The only featured “disabled” on a site where the license is not active is in-admin updates and that is only because a license needs to be validated before an update can be permitted.
Hope that make sense!