On 11 June, 20:46, Clive Page wrote:
I went from London Bridge to Charing Cross today, showing my Oyster card
at the manned barrier at Charing Cross. *The man on duty told me to
touch it on the pad, but I refused pointing out that I had not touched
in (as I changed directly from a FCC train there). *He asked me where I
had come from: London Bridge was obviously the correct answer, as he
then let me through. *This does suggest that SE trains were being
selective in allowing Oyster card usage.

I undistinctly heard an announcement at Peckham Rye today, which may
have referred to Southern or South Eastern or both, saying that PAYG
would be accepted as long as your journey was similar to your LU
route, or something on those lines.

As for touching at Charing Cross, your Oyster would simply be rejected
unless it had a valid Travelcard on it. It wouldn't have resulted in
an unstarted PAYG journey. I don't know why staff would suggest that
you touched unless they assumed that you had a Travelcard.