2016 savanna. A/C stops cooling completely after a period of time.

What is your question?

Purchased used. Problem starts as a loud buzzing when it is at an idle. Noise stops when engine speed is increased. After numerous cycles of this, it stops cooling altogether.

What makes this problem better or worse?

Nothing makes better or worse

How long has your 2016 Chevrolet Express 2500 had this problem?

2nd time in 12 months