Seems to be an under publicised issue with GNE ticket machines corrupting POP PAYG cards. Nexus are clear where the problem is yet GNE drivers are not aware and allow cards to be used then corrupted - It has happened to me twice now. Sort of defeats the idea of the POP PAYG cards.

GNE also had issues with POP Blue for a while but it didn’t corrupt them as far as I’m aware.