Just happened to me this past weekend. 2014 Sierra SLE with appx 27k miles. Air blowing warm. Took it to dealer and said condenser was leaking. Didn't say how, didn't ask. Thankfully all covered under warranty. According to job sheet they replaced condenser, Freon and recharged.
Haven't posted in a while...thinking of a new wheel setup. This is my current setup.
2.5 rc level
275/70/18 cooper st Maxx
Moto metal 962 18×9 +0
The method wheel setup is growing on me. Want more of a "raptor" looking setup.
7k mile service and outstanding recalls (transfer case/odo peek) gas definitely feels a little more responsive. No lag or delay compared to few hours before. Still all good though.