The 990v6 uses a pretty soft leather on the toe box, and that's actually kind of by design - it's meant to be comfortable right out of the box rather than needing a break-in period. The downside is that softer leather creases more easily, especially in that area where your foot naturally flexes when you walk. You're not getting a bad pair; this is just how the shoe ages. Most people's 990v6s look like that after a few weeks of regular wear.
The good news is creasing on leather sneakers is pretty much cosmetic and doesn't affect how the shoe functions. If you really want to minimize it, cedar shoe trees or even just basic plastic ones can help maintain the shape when you're not wearing them. Stuff them in while the shoe is still slightly damp after wear, and it'll help slow down how pronounced the creases get. You can also try leather conditioners made for sneakers - they won't stop creasing entirely, but they can keep the leather looking less dry and cracked over time. That said, honestly most people just accept it as part of owning these shoes. They're designed to be worn and lived in, not preserved in a display case.