I have been using my card on TfL and National Rail in London. I have now been subject to two on-board revenue checks and the card has failed on both occasions. Despite having properly touched in with the card on both occasions, the card fails the on-board checks and gives an error on the inspector’s device. The card works fine at all ticket barriers. On both occasions the revenue inspectors have been fine about it but people could easily start getting penalty fares (or worse) if they are not believed. This should be addressed if at all possible.