I see that both Epsom and Cuffley are now listed as Zone 10 stations on your fare finder, which does indeed put an end to inboundary Travelcard validity at those locations (TfL buses aside). Did GTR make those changes in the March 2026 fares revision?
etr221, since their previous Zone 9 status was only ever a half-open secret I suspect GTR felt their recent rezoning didn’t need any publicity beyond messages to fares staff and other retailers.