We have Frequent Traveller tickets that were extended from the first lockdown. In our case until 27/6/21. Following the news yesterday I tried to book out late June and back early July only to be told my account had expired. Cut a long story short, I managed to contact them eventually via chat, I hate that!!!!, to be told that although yes, all FT tickets were being extended until 31/12/21, that process won't take place for several weeks!. She also confirmed that there is limited FT space on each crossing, and once that space is allocated there is no more. I asked what would happen if all the space was allocated by the time the tickets were extended, and she replied I should book early to ensure a space. The conversation then started going round in circles.
In our case I eventually booked to return before the existing expiry of our tickets
In our case I eventually booked to return before the existing expiry of our tickets