Hoy to the sketchup website, log into your account, then go to plan settings, there your sketchup license will be shown, to the right of your screen it should say edit plan settings, click there and go to manage seats.
The OP has a Classic license so instructions for subscription don’t apply.
I would guess that the changed way SketchUp looks for an Internet connection is part of the problem. There has also been recurring problems with the older license management servers. @colin , What is the status here?