I bought a iPhone XS recently ... and I don’t use it roughly at all... recently I found 2 spots on my rear camera glass ... I don’t know if it’s a scratch ... it goes when I wipe it ... but come backs again when it has finger print on it .... its frustrating me soo much .... and I haven’t heard anyone who has scratched their camera lens as it’s sapphire glass. How did this happen to mine only ?