Two Computers Activated With The Same Product Key

Hello ,
I have registered for this forum for a long time, but I rarely post it. To this day I have encountered problems, but I cannot find a topic corresponding to my problem. Please allow me to drive new miles ...

I upgraded mine from Windows 10 Home, to Windows 10 Pro. Windows was oringally installed as fresh on both computers.

Bother computers had their own product key.
I have two Windows 7 Ultimate key, which I used to upgrade my Windows 10.

Yesterday, while working on my Sister's and her husband's computer, I decided to give them an upgrade, and chose the Windows 7 Ultimate one, to see what'll happen. It worked.

Weird thing is, the product key I used, is changed (not the same as the one I entered), probably becuase there is no Ultimate version of Windows 10.
A even weirder thing is, both computers have the same product key. My computer was off when the other computer was being activated. When I get home, I expected and activation issue on my computer, but so far none.

I tried to change the Windows 10 product key to another Win10 Pro, but when I use ProduKey, it still shows the same key.

Is it possible to dig out Wordperfect v7 Product Key? I tried Produkey.