I am attempting to book rail tickets online for 5 adults on 19 June from Rome to Sacile. I selected train / time, entered each name, and selected seats for our family from the available business class seating. When I attempted to continue, I received error message informing me no seats were available for the train I selected. Ok, so I went back and selected a different train / time, same process, selected seats and again received error message saying no seating was available on train I selected. I tried 4 more trains/times, and all resulted in same error message. What is happening?