Okay, so I I am pretty sure I have already made two threads about cards curving, but I felt the need to share this one here.
I just got a blaster of 2017 Bowman today. I opened all the packs, put them in order, and then placed them in a neat stack on my coffee table so I could do some other things around the house before I put them away. I kid you not, the base cards started curling right before my eyes! Just like my 2017 Topps and various other newer sets. (again the curving is very minimal but you can certainly tell they aren't prefectly flat like out of the pack.)
So now I know for sure that the way I have been storing them in boxes is not the cause of this. (although wise members of this site had already convinced me the box wasn't the issue.)
So either these cards just naturally curve on their own, or living on a massive concrete island in the middle of the desert is not conducive to keeping trading cards completely flat.