Reproduction steps:

1. Add the attached shader "GLES3_GLCore_missing_Globals_reflection.shader" to a project
2. Select the shader
3. In the shader's Inspector Window select the dropdown next to "Compile and show code" and tick "Custom" and "OpenGLCore" or "GLES3x"
4. Click the "Compile and show code" button

Expected result:
The "Compile and show code" output for OpenGLCore and GLES3 contains the 'Constant Buffer "$Globals"' reflection section

Actual result:
No reflection for the Globals constant buffer is in the "Compile and show code" output

Note: if the usage of "myStruct" is commented out from the shader, the 'Constant Buffer "$Globals"' section will appear in the "Compile and show code" output

Reproducible in: 2021.2.0a7, 2021.1.0b9, 2020.2.6f1, 2020.1.17f1, 2019.4.21f1
Couldn't reproduce in: 2018.4.32f1 (Doesn't output constant buffer information)