Was your car parked for a long time (as few as 3-5 days) without being
driven? I've seen this primarily in cars that have set for long periods
of time. The pressure put on the lifters by the springs on the open
valves causes the lifters to bleed down over time. If they get too low,
it takes some time (or driving) for them to pump up. As for the thing the
shop did to correct, most likely they drove the car hard for a few miles.
Most likely, there's nothing wrong with your Santa Fe. You probably just
let it sit a little too long without starting it.