The tire pressure was 5psi below recommended for the 4 tires. That car was at the dealership for a routine service a few weeks ago so they must have adjusted the tire pressure lower but I have no idea why.
I've had the same thing happen, it is because I set the tire pressures when the tires are stone cold, first thing in the morning. On the rare occasions it goes to a dealer and they set the pressures, they set it to the cold pressures, but the tires are warm or even hot from the half-hour drive there. Then they cool down and the pressures are low. So I ask them to not change the tire pressures but I check anyway the next morning.