Steps to reproduce:
1. Create new HDRP Template project
2. Move static object
3. Save the scene
4. Enter Playmode
- observe that lightmap reference is lost at this point

Expected result: Lightmap reference should not be lost when static object is moved

Reproduced in: 2021.2.0a17, 2021.2.0a14
Not Reproducible in 2021.1.10f1;

Notes:
- Also reproducible in Built-in RP (see case comments).