Several visitors have reported problems when touching out and back in again at the same station. The system tries to combine the two journeys into one, often resulting in a pair of incomplete journeys when you get back to your starting station. But if your journey included an OSI en-route then you may well end up out of the system altogether and be given a penalty fare!
I’ve had reports of this happening at Marylebone, Tower Hill, Stratford, Lewisham, and most recently Blackfriars NR where my 16-year old son had an issue which put him at the mercy of Southeastern RPIs later on in the day. I sent TfL a FOI request to try and work out what was going on, but all they can say is that it’s probably emergency OSIs which by default allow re-entry and continuation of journey. The trouble is that in some of these cases there was no obvious emergency to justify an EOSI.
I have fed back a response to the FOI request saying that it is very worrying when unexpected behaviour ends up with a penalty fare being issued. I will also be following up my son’s experience with the helpdesk trying to find out exactly what went wrong.