The 2020 will work as 30day trial.
So are you looking for a fix for 2019 ?
The Band-in-a-Box 2020 build 422 is in beta testing now for Big Sur.
Depending on how much work was done on this to fix it for Sur and if that can be applied to 2019 then maybe they might make a 2019 fix ???
But 2021 will be released soon.
There used to be an app only upgrade for $49