Temperature gauge for outside temperature

Yeah... Let them know... It's the only way to get your money's worth when you buy brand new. With the amount you paid I'd be making their service department work on even the tiniest problems as often as possible.

 

They can test the probe to make sure it works, and they can verify that it is mounted correctly, because position matters for those things.

Lastly there is an electronic setting- a fudge factor to offset an error elsewhere.

One way or another they should be able to fix you up.

 

Based on an actual, accurate thermometer, your phone's weather app, or?

 

Weather app's thermometer might be far enough away to be a few degrees different from your location.