1. Download 917220 repro.zip
2. Go to Assets->AssetBundles->Build AssetBundles
3. Build the project to iOS
4. In XCode, upload the app to iTunes Connect
5. Open the app on a device via TestFlight
6. After a few seconds, a white Unity cube should appear in the screen
7. In Unity Project Window, navigate to Assets->assetbundlesample->assets->MuCube.prefab
8. In Inspector window, change "MyMaterial" main color to red.
9. Repeat steps 2-4 (but after step 3 change the app version from 1.0 to 1.1)
10. Download the app's update in TestFlight and open it
11. After a few seconds a white Unity cube appears on screen

Expected results: the cube that appears is now red
Actual results: the cube is still white

Reproduced on: 5.6.1p1, 2017.1.0f3

Note: does not reproduce with a simple local build.