The problem could come in because you are a Member. Your wikitree ID will change and you will not be able to 'easily' see your earlier contributions. After doing it, make sure that you can log back in from an incognito browser window.
To see your earlier contributions, you can go to the Contributions on your new wikitree ID and change the URL to use your old wikitree ID. If you have any problems logging in, send an email to info @wikitree.com