Today I purchased a ticket from the station to Charing Cross, unlike yesterday when I bought one, the ticket had in bold "SOUTHERN ONLY" which made me a bit dubious about changing at London Bridge to use Southeastern trains onto Charing Cross.
Luckily the gates opened at CX and a ticket inspector didn't come on the SE train, but it is concerning if FH users could stump up a ?20 penalty fare by accident because of these changes to the tickets.