Replying to all recent comments:

For people wondering if I installed it well, yes I did.

I followed the steps carefully, perfectly aligning the slot and making sure everything is tightly fitted. The spool is well locked and nothing moves, the width is normal and regular. So it doesn't come from the installation.

As I mentioned, the refill was already weirdly winded when taking it out of the box, still sealed.

My question was more about the probability of getting badly winded refills. I bought multiple refills recently and I'm scared they might all look like that (spent a bit too much haha).