I would suggest manually checking all 4 tire pressures. You can also call the service center and have them check remotely it’s likely they didn’t change one of the settings between 19” and 21”. Or that one of your wheels might have the wrong or bad tpms sensor! From what I know they have a few places to make the change like the air suspension settings etc. above and beyond the one place we have control over which is in the tire pressure monitor reset screen.