The way I understand it and the way it worked for me is that when it is installed on a copy of SU and installed on a copy of another version of SU, on the same computer, it uses a separate license. The copy of SU2019 and SU2020 on the same computer use separate licenses. If the SU2019 is deactivated, which it will automatically at some point, and you haven’t deactivated it on that version, you may have to get with customer service to correct the problem.
To make things worse, it won’t let you purchase another license in the EW either. Perhaps there is a way to purchase some kind of corporate license. But, you cant just purchase it again, believe me I was willing to purchase an additional license for the additional licenses.
When I tried to call there was an extended wait and they gave me the option to email them and they responded when they were available.