I’ve seen this often so it’s quite normal? But it would drive me crazy. I’m a bit OCD though. It really depends on one tolerance. I rejected a bunch of minis with bulging side in a store, refusing to believe that all will eventually bulge as we use it though it might be true. I also recall people suggest ‘reshaping’ it by filling the bag with clothes, put inside the box and fill the box with clothes and don’t forget to press in the sides. Leave it for weeks. Personally, I would choose the perfect one when purchase, mine are still in perfect shape after 2 years of normal usage. I have M/L flap with bulging sides (the last one in store and I hunted that particular color) but only near bottom part. It’s already driving me crazy, lol.