I've successfully added Garmin Pay to my ForeRunner 255. I can Tag On (i.e. get admitted and charged), but I've never been able to Tag OFF. Journeys have all been less than an hour so the PIN ought to have been still active. The associated physical card still lets me tag off.
This is not an issue with a single station; it has never worked exiting any station. , I've had to stop trying to avoid inevitable full-journey charges (for not using the same device at both ends)
TFL tell me there are no known issues on their system.
Assuming I haven't just been unlucky/careless interacting with every turnstile, since I've deployed my FR255, any ideas or suggestions?