Lube will help it corner cut, so I would try putting in some lube. On the SCS side of lube: Martian or Galaxy. On the Cubicle side: DNM-37, Lubicle-1, or Lubicle Silk. I haven't tried Lubicle Silk before, so I can't say the exact results it will give. I use SpeedCubeShop Cosmic Lube often, and it works really well, so if you haven't used any before, then you should try it sometime! But like
@Duncan Bannon said, your tensions could be way too tight, so keep that in mind