new iPhone 11 cracked back glass for no reason

Hello. Recently I got iPhone 11 128gb. After opening the box and upgrading I left it on a box in a safe place. Since I had my old iPhone I did not use it for a days. Next time I took it I noticed two small cracks on right side back glass. I also noticed a small imperfection on left side of back casing where the metal touch glass. Could that be the issue? The phone was not in use and I dont know how did that happened? Can please someone explain. The phone is brand new!!! Will warranty cover that?!?

Please check and get back to me.

Regards,

Mitja