Saint Michel - Notre Dame

My family was traveling in Paris, and at the Saint-Michel Notre-Dame subway station my wife and I were with our daughters, aged 6 and 10. When we entered, the ticket system only offered a Navigo card option, and there was nobody around. My wife bought tickets on the SNCF app for two adults and two kids, but after loading, only one adult ticket and one kid ticket appeared on the phone. We couldn't get the tickets into Apple Wallet, so we called the SNCF controller for help before entering. The controller let us through with their card, then immediately checked our tickets and said we didn't have enough valid tickets. They threatened a $50 euro penalty for each person without a valid ticket and said they'd call the police if we didn't cooperate. We tried to explain things to other SNCF uniformed staff, but they said it was our fault. We were international travelers asking for help while trying to work out how our tickets worked, and we had proof of purchase. Even so, the controller let us in and then inspected us with a machine and fined us. I believe this happened to others too: we noticed travelers from Ireland and other parts of Europe being fined $100 Euro or more. It seemed to us that SNCF controllers were using the system to target people unfamiliar with it. They scared our kids by saying the police would come and deal with us, and my daughter cried. One agent was a Black man wearing glasses. Be aware of him!