Your account was activated on December 13th 2022. Is this likely to have been you? For privacy reasons I cannot see what email address was used for the activation, but our experience so far shows that accounts activated that long ago are mostly stolen (i.e. someone used your username and password to activate it).
I've cancelled the activation. Please use that same link to activate again. When it redirects you to the discovery+ site, use the "Sign in" link in the top right corner to associate your subscription with the discovery+ account you've already created.
