Can't see licenses on keys anymore

I have always owned two Steinberg licensing keys (one used to be the activation key for all of them and the other blank) and have used a number of older plug-ins with previous versions of Cubase for my music projects.
I’ve recently discovered that the licensing system appears to have changed, and I’m unable to access licence support in the way I used to. When I check my Steinberg account, the licences are listed, but they seem to be associated with a different USB-eLicenser serial number than the physical keys I currently own. That’s the first issue I’m trying to resolve.
I’m happy to upgrade to the latest version of Cubase. However, I understand that this won’t automatically provide access to older 32-bit versions of Cubase or allow me to run my legacy 32-bit plug-ins. I would very much like to reopen some of my older projects in order to create stems and archive the material properly.
Could you please advise on the best way to:
Resolve the licence key serial number discrepancy
Access my older Cubase versions
Enable temporary use of my 32-bit plug-ins so I can export stems from legacy projects
Any guidance on the most practical solution would be greatly appreciated.

Upgrade to the new version is fine I probably need to buy a new PC to register it too but then I want to access my old files please?!

Kind regards,
Roland Saunders

Have your reviewed this info?