I noticed the same thing with the K&N drop-in I used to have. Short story, you're ok.

Not as short story, the outside edge of the K&N was thicker. The filter had a tight seal with the bottom airbox and the top airbox fit tight on the filter; since the fiter was thicker the two plastic halves of the box didn't touch but the seal was tight anyway.

My problem was that one of the clips wouldn't stay on with the thicker filter. But after watching it for a few weeks the other clips were keeping the air box sealed, so no worries.

Double check yours to make sure the halves are sealing tight to the filter. If not then you'll need a new one.