Things have taken a bizarre turn. Yetserday I found that my season will not operate the 'suburban' gate line (opposite platforms 9-12) at Victoria, but it will operate the 'mian line' gate line (platforms 15 - 19)! I tried every gate in the suburban row and none worked - all the ones I tried on the main line set worked. So - the ticket now appears to be even further restricted than I had previously realised! I have only just discovered this after so long because I have become so fed up weith the Redhill line's service that I have started using the more laborious but much more reliable Betchworth - Dorking - Epsom - Victoria route, where trains arrive at platforms 9 - 12, rather than 15 - 19 for the Redhill line.
I find it completely baffling (and very annoying) that this ticket seems to have such a ridiculous degree of unavailability at stations (and even within stations) at which it is valid! Southern are going to get another rocket today!