strange iPad build problem

This is a very strange problem with a previously working app, built for iPad.

The app has a bunch of cylinders. In LateUpdate, the sizes and orientations are calculated and the cylinder attributes are set. In the editor everything is fine, but in the built app on the iPad the cylinders are completely hosed.

It's this app in particular, as a test app does what it's supposed to do. There's no conditional code anywhere so it can't be a platform issue. Any advice on where else to check?

Note: I'm still using 5.6 because I have a Pro license.