You’re welcome.

If you were automatically logged in to the forums, then in effect you should be able to get into your my.avast.com account also if it remembered your credentials.

Try opening your avastUI and click on the image pic / User Name (image1 attached), this will be trying to connect to your account but it keeps spinning its wheels. Just click on the View Account button (image2 attached), that should open your my.avast.com account in your browser, it did for me. Here you should be able to add the new email address as I mentioned earlier.

I hate this massive bloody UI these images are resized to 60% and I hate it going centre screen every bloody time.