I and my sister bought two new Samsung galaxy A71 phones

[JustSomeone]

I'm noticing something weird with my phone. We bought the phones 10 days back. I took the black one while my sis took the blue one. We even bought the same phone covers. I was casually  testing the camera for both the phones. I noticed that the pics taken by my cam (64 Mp ) captures clear details on only one half of the pic. The lower half, especially  around the edges seem to be blurry. While pics taken from my sister's phone have neat details for the entire picture.  

I've literally taken more than a thousand pics from my phone to verify this, and this is indeed the case. I've tested taking pics from her phone as well under the same conditions, almost the same angle, lighting conditions, 64 MP mode, with or without best shot suggestion, pro mode, etc but everytime pics from her camera appear to be well detailed for the entire pic. 

Whereas the pics taken from my phone have blurs in one of the two halves of the image. If the lower half is clear, then the upper half will have slight blur and terrible blur around the upper half edge of the pic and vice versa. Same I've observed with ultra wide camera as well. One half of the pic is more detailed than the other half. I suspect that the focus area of my phone's camera is small. 

I'm not able to understand why there's a quality difference for the same phone model under the same condition. Is my camera defective ? 

PS: I've even tried resetting the camera settings but to no avail. 

Could anyone please enlighten me on this ? 

[Anikroyale]

Are you using a camera glass protector? If not, take both the phones to a service center and show them the difference. I think your phone has some camera defects. Also, pleasevpost pictures here so that we can analyze it better.

P.S. The title should shart with "My sister and I" 🙂

[JustSomeone]

both of our covers have camera protector intact. I was also suspecting the cover is at fault. because although we are both using the same cover from same brand, I see that my pics taken in ultra wide mode has some dark marks at the edges due to the cover while they are absent in her case ( ultra wide mode ). maybe my cover is defective. I'll take pics again after removing the cover.

[JustSomeone]

I took pics sans cover and the result for is still the same .

[Anikroyale]

Can you provide some pictures?

[JustSomeone]

adding pics distorts them for some reasons I don't understand. but there's a difference in pic sizes in both the phones. pics taken from my sister's phone have larger size compared to mine. camera settings are same in both. however there's a significant difference in size ( MB ). does it mean her phone captures more detail ?

[Anikroyale]

I think your one captures in normal mode while her one caprures in 64 MP mode.

[Anikroyale]

This is the only thing which makes a difference in size of the pics.

[Anikroyale]

It should be of more size if it is in 64 MP mode.