Why my iPhone 16 Pro is not turning on?

This is the second time my brand new iPhone 16 Pro won't turn on. I had to do the method Apple recommended (volume up, down and hold the side button). I did it multiple times before it actually worked. I bought a 20W USB-C Power Adapter from the apple store trying to fix the original problem but it happened to me again after I got it. Is anyone else having this issue? If you are, how did you solve it? Thanks.