Arkham Origins help

I have been replaying Arkham Origins through the PlayStation plus streaming service, I have beaten the main story and was going through mopping up all the side quests. I’m just about done but I need one more Extortion File found on pioneers bridge. It’s inside the train station, I’ve looked up guides for this specific area and file, it says it should spawn inside the train once the story is complete and the hostages are gone form the train. I am inside the train but the game insists that I need to disarm the bomb and my file was not spawned in. I have tried reloading the game, reloading checkpoint, and dying to fire near the train. Is my game bugged forever or am I missing something entirely? TIA!