A slight display gap observed on oppo find x9 pro

Hi guys bought my first x9 pro trading iphone13 I have removed the screen protector given out of the box and applied a tempered glass. However I noticed very tiny curved display gap at the top and that is definitely not from the tempered glass. I'm just curious to know whether it is really an expected thing? Or should I contact service centre immediately The gap is soo tiny that we didn't observe while unboxing. In direct sunlight I figured out some dust particles that is where I discovered this. Note: the gap starts exactly from the white stripe ends near to second white stripe.