Cardboard for Unity is cross-eyed

I’m making an Android app intended for use with Google Cardboard, and everything works fine in the editor. However, when I build it and use it on my phone, the left and right eye images don’t quite line up, giving it a cross-eyed appearance. Both “eyes” seem to be pointing in different directions. This happens with both my own scene and the demo scene, as well as a couple Cardboard apps I downloaded from the Play Store. This would lead me to believe that this is a problem with my device, but most other apps work as intended. What am I doing wrong?

The solution is to set the DPI to 400. OnePlus reports a higher DPI (480) than the device really is.