bizarre behavior in built app

Starting with an app that runs fine in the editor. Gameobjects show up sized and positioned where they’re supposed to, text strings get updated, etc.

Build for iOS - it’s all gone. The gameobjects are whacked, even though debugging says their parameters are being set. Text strings don’t get updated.

There’s no conditional code anywhere, so it isn’t a case of code not getting included for the build, it's a really straightforward build app workflow. When it runs in the editor, the console log shows that the numbers are updating as expected.

But when the app runs on the device it's whacked, even though the console log still shows the expected numbers.

This happens with 5.6.3 or 2017.1, going through Xcode 9 beta 6.

Any ideas?