Pink marks on iPhone 15 screen when the phone is hot and in the sun

I recently got a new IPhone 15, my very first time buying a brand new phone. I get these pink circle marks on my phone screen when it is hot and in sunlight (happens in the shade too). The photo doesn’t include the horizontal lines so I drew where the lines are as well (2nd pic)

I went to apple and they were confused and were unsure of this problem, so they sent me home with a new phone since it has only been a week with this phone. The marks have shown up again in the same spots as before. They’re really dark and very distracting.

The marks move when I change apps so I’m not sure it’s a physical thing more like a software thing I am guessing.

I’m slightly confused on how this happened twice and I haven’t seen anyone else post about these marks before. I’m pretty disappointed since this was a big purchase and it is really bothering me.