Upgrading from Passolo 2018 network license to 2022

RWS notified us about the new Passolo 2022 and we would like to upgrade from our Passolo 2018. According to the same mail we should be able to use 2018 and 2022 side by side, retaining both licenses.
But when we try to upgrade our network license, a message box appears saying that we must first return "all activations currently in use".

Does this mean that we cannot retain the 2018 license?
If so, can both 2018 and 2022 run on the 2022 license?

I found this about a similar case with 2016 and 2018

Is this procedure applicable to 2018 and 2022?
I.e. will there be a "Use Passolo 2022 license" checkbox?