quits running when reaches operating temp
That has to make longer drives difficult,
Hopefully driving to the dealer for warranty work is a short enough drive you can get there.
Darn it, you have a 2021 Hyundai in July. I remember when the new model years didn’t come out until Oct/November.
Model year 2021 is the default selection when a year is not selected, some people don’t know the model year of their vehicle.
^ This +1. If your Sonata was purchased new it has a 10yr./100k powertrain warranty, if you’re the second (or third) owner it’s 5yrs./50k. If it’s no longer under warranty take it to the nearest independent mechanic.