Paramount+ subscription not recognised

I recently cancelled our Paramount+ subscription. In Settings > [my name] > Subscriptions it correctly shows ‘Expiring 20 December’, but when I login to the Paramount+ app it doesn’t seem to know I’m already on a plan and insists I sign up for one. I still want to use the plan up until 20 December.

What can I do to keep using the plan? Is there any way I can find out through Apple what email address the subscription is under? I’m currently logging in with a Hide My Email address, but I’m think maybe I signed up for Paramount+ with a different email address.