Checking on an upcoming flight booked from Punta Cana to MDW. I see the price has gone down (booked for four people and checked new fare for four people). Great. Go to change reservation, select new flights and the cheaper fare doesn't show up, still the fare I paid.

What's interesting is the fare is even lower when a roundtrip is selected rather than a one way. Here the fare is $30 lower for the same flights, then if a one way is selected.

Does this make sense?