Now, when I log to Professional account with magic link I can go no further:

Menu bar displays only GAJIX (loops back to same screen) and Menu: Offers manage / delete account and log out.

Body displays 'Start your 30-day free trial - activate your account to begin learning $20 / month, start free trial button gives:
This XML file does not appear to have any style information associated with it. The document tree is shown below.
<Error>
<Code>AccessDenied</Code>
<Message>Access Denied</Message>
</Error>

So, basically routed to a cul-de-sac..
not..learning..much ;)