My iPhone 13 Pro Max is doing the same thing.
Random restarts, pink screen on some restarts, other times it just turns off.
Took it the to the Apple Store yesterday. They replaced the "rear system". I then had to do a restore.
The tech said that means about the only thing that wasn't replaced was the display screen.
It has now been about 24 hours and no problems. I will update this post in about week or before if it starts happening again.
I first went to our Verizon store and they said they would replace the phone. But he said there is a chance I could get a refurb phone. So since it is still covered under Apple's first year warranty, he suggested I take it to the Apple Store first and see what they would do.
Will keep this post updated.