Pit2Home:

It looks like this is a case of rather full flights as opposed to US's pricing. In checking your outbound leg its only showing 7 available seats in the Y&B buckets. All the other coach class seats are already 0'd out. On the return the lowest available fare is in the Q bucket. The US FCO flight is very popular... you're just running up against that popularity. Will be interesting to see how the MXP flight affects loads on the FCO run.