VST Connect Pro 5 Installed but not functional

When I first installed VST Connect Pro 5, it worked as intended.

Now when I select VST Connect Pro from VST Cloud, all the options are listed, but greyed out. I am forced to use VST Connect SE.

I have Cubase 12 Pro.

Did you recently update? VST Connect v5.6 is now called VST Connect Performer. It sounds like you might have updated the software but missed the step to migrate your license to SAM.
It’s a very straightforward process - it’s outlined in the Release notes.
If you don’t have them handy, go back to Steinberg Download Assistant, scroll down to the Cloud Section, and download them there.
In any case, it’s a very simple process. From memory, you just need to open SAM, find your VST Connect license in the Not Activated section, and click to activate it.
You’ll be up and running in a few minutes.

That is not true, VST Connect Performer is a simple, free application for the Performer (Talent), which connects with the Studio using the VST Connect plugin.
Other than that, you are correct, and registering via SAM is the right way to use the new license scheme, thanks for helping!