Things like this are more than just mildly infuriating to me as a collector. To help all of us calm down after the shock and also to redeem Carlsen Comics, at least a little bit, I present to you my Akira "Original Edition" also known as the "Phone Book Edition". The layouts of the issues are not accurate to the millimeter but the production tolerance is definitely precise enough to not feel bad about it.
This could be a case of them cutting multiple covers at once.
I had the same problem with jeans. I order the exact same style and size, but they don't all fit the same. When I spoke to a Levi customer service person, they said they have multiple layers of fabric piled on top. Then the cutting blade presses down, and the fabric bends. As the top one is to short on measurements, the bottom most one is to long. So you want one in the middle.
I know paper isn't fabric, but it could be something similar. It's speed and efficiency over accuracy.
Probably bait but: Replacing a book cover is not a beginners task. A printer capable of doing book covers without looking like shit isn't a household size item or household price and the printed result is different from the source image. Even if you scan the book at the highest resolution you will get the print pattern and not the pixels. Editing will be a shit show if there is a noticeable pattern in the print. Basically guaranteed to look like garbage if you don't put an exorbitant amount of time in. Or if you have a book printing business but then the copyright lawyers will come for your first born.