You should probably file a support request at SketchUp. I understand their offices are closed until Tuesday for the holidays. Perhaps @colin comes here before that but it’s his free time too.
Make sure the product access to the Studio plan is assigned to the email you’re using in the Members section of the account portal.
Then, in connect.trimble.com sign in with that email address.
The standard SketchUp project might still be under the free account (check settings > project details)
Either switch there or better, create a new project and choose the right license.
Make sure you save the settings when switching account ownership of the project.
I don’t think you can delete Free entitlements. You could delete the entire account, but that would lose everything, which I think you found out!
The email you use in the forum is the one that has a Studio subscription until May. If you are looking in the account management page, it will be listed under the WHITE PEAK DESIGN account, not the Personal one.