How to reproduce:
1. Open the “WebGL_Shader_Bug“ project
2. Open the “SampleScene”
3. Enter Play Mode and observe the Game view
4. Switch Platform to “WebGL” (File > Build Settings > Platform > “Switch Platform”)
5. Build And Run (File > Build And Run)
6. Observe the Player

Expected result: “TemperatureShader” is visible on the “Plane” GameObject exactly like in the Game view
Actual result: “TemperatureShader” is not visible on the “Plane” GameObject

Reproduced with: 2021.3.28f1, 2022.3.4f1, 2023.2.0a22
Could not test with: 2023.1.3f1 (“TemperatureShader” throws “'OUTPUT_SH': Too few arguments to a macro call” error → Textures are pink)

Reproduced on: Windows 11

Browser reproduced on: Firefox, Chrome, Edge

Notes:
1. Not reproducible on the “Windows Standalone” Platform
2. Not reproducible when modifying “TemperatureShader” → see internal comment regarding this
3. Reproduced with “Linear” (Edit > Project Settings > Player > Other Settings)
4. Could not test with “Gamma” Color Space → the “Plane” GameObject is rendered with a solid black color