Android Flip phone air pocket

I have the start of an air pocket in the seam of my Samsung flip phone. It goes about half way across and I am worried it will get worse. Has anyone had this before? The phone is less than a year old, should it be covered by warranty? I have never dropped or damage the phone, have not had near any liquid. I’m trying to figure out how to fix it or if anyone else has had to deal with this. Any comments appreciated.