Reproduction steps:
1. Open the attached project "texcoord lm.zip";
2. Build both scenes for iOS;
3. Open the project on the device;
4. Switch between two scenes using the "Load Other Scener" button.

Expected results: both scenes have their lightmaps.
Actual results: One scene has its lightmap stripped away and the object is rendered black.

Note: works fine in the Editor.

Reproduced on: 2018.1.0a1, 2018.1.3f1, 2018.2.0b6, 2018.3.0a1.
Not reproduced on: 2017.4.4f1 or lower.
Reproduced with iPhone 7 (iOS 10.3).