How to reproduce:
1. Open the project attached by the user (Puzzlemon.zip)
2. Open the "scene1" Scene, play it
3. Observe the green Tiles in the Game View
4. Stop playing the Scene, Build the game for WebGL
5. Launch the build and observe as the green tiles are not visible

Expected result: Tiles added by script function in WebGL builds
Actual result: Tiles added by script do not appear in WebGL builds

Reproducible with: 2017.2.0a1, 2017.2.3p1, 2017.3.2f1, 2017.4.0f1
Not reproducible with: 2017.4.1f1, 2017.4.5f1, 2018.1.4f1, 2018.2.0b7, 2018.3.0a1
Could not test with: 2017.1.0a1, 2017.1.4p1 (No TileMaps)

Notes: The tiles are visible on builds for PC, Mac, and Linux standalone builds.