Account Activation Failures

I am a new user on Musescore, and after creating my account I received the confirmation 'activate your account' email to my email address.

I've clicked on the button 'activate my account' and it then sends me a welcome message to my inbox.

However - when I go to Musescore, it gives a large yellow banner across the page 'your account is not activated.'

I've tried logging in from another machine and rebooting, same problem.

Can anyone offer advice?