Had a tune up done. New tensioner belt and pulley and harmonic balancer installed.
sometimes it still squeals loudly for about 20/30 seconds then runs fine, no noise.
Was told it's ok cuz it's new and it will stop.
Thoughts?

Is it the pulley rotation noise or belt squeal?

If it's squeal, your belt tension is wrong.

If the belt is old, it may have become hard and slick. Just another possibility.