Front cam defect (having a purple dots)

I use my iphone 12pro max front camera frequently for recording and noticing a purple dots on it since its under warranty I send it back to the store then they fix it, but after few weeks it came back the. I have to send it again. I decided to upgrade to iphone 13pro max and im very disappointed coz just after a week it seems to have the same problem and im sick of it .