Software Upgrade Misunderstanding?

[pyst7lot]

I think I'm confused about paying for upgrades.
I originally bought Expert Lotto 5.10 in 2019 to expire on 22/4/2020
Then I paid for an upgrade in 2021 to get Version 5.11 and the license expiration is 14.1.2022

Now if I install EL on a new computer I can only use the 1st license key to install Version 5.10
My upgrade licence key no longer does anything. I did expect to be able to install 5.11 without being able to install any new plugins.

Am I expected to keep paying the $20 upgrade fee to maintain a Version 5.11 installation and in effect pay for Expert Lotto all over again after 4 years!
With no new versions since 2020 I hardly expect to pay more.

The odd thing is that the installation on my other computer is 5.11 using these expired licence keys. Puzzled!

Edit: I should add that as powerful as the software is at doing amazing things it is really only a toy. I'm still waiting for amazing results. lol