It’s the lever/rod from the key barrel which moves when you turn the key. That rod is fouling on the vertical rod. Nothing looks bent or damaged.

Yeah I’ve got the diagram already. When assembled as it should be the key doesn’t turn.

My Bongo door locks would only turn in one direction and the central locking wouldn't operate. Inside the door I disconnected the rod from the door lock and found the key correctly turns the lock in both directions.
The rod appears to be prevented from travelling in one direction. With this rod ...