iPhone 15 Pro Max has inconsistent 4k video

I am getting inconsistent results when filming 2 videos using the same lighting and shot within minutes of each other.... The first one is kind of grainy when it comes to skin tones (my hand specifically) and you can't even see the mole on my hand (it looks blurry)..... The second video starts at around 30 seconds in and that is when the 4k is normal and perfect!

The differences don't show up in the couch etc... but on my hands... you can see how blurry my hand looks in the first clip and much clearer in the second.

https://www.youtube.com/watch?v=S7bWqLg5pes

I noticed that when it was grainy the camera was using the 33mm wide lens (I guess I was zooming OUT) and when it was normal/good it was using 24mm lens... So should I avoid zooming out? Can zooming out cause this amount of pixelating when using a ringlight at night? It was pixelating and noisiest in my face but I don't want to show myself so I blurred it but you can see it happening in my hand.

I was using the same ring light in both videos and never had this not be enough lighting for any other camera...

Is this a known problem with the iphone 15 pro max? Or do I have a lemon?

[Re-Titled by Moderator]